Definition of parallel in English:



  • 1(of lines, planes, surfaces, or objects) side by side and having the same distance continuously between them.

    ‘parallel lines never meet’
    ‘the road runs parallel to the Ottawa River’
    • ‘The basic idea was to stay parallel to an existing trail by keeping the edge of the paper between the two sensors on one side of the chassis.’
    • ‘In geometry like this, all lines intersect at infinity but in usual geometry parallel lines do not meet.’
    • ‘The parabola results when the plane is parallel to a generating line of the cone.’
    • ‘When an object is at rest on a stationary support, the thrust line is parallel to a radius of the planet, i.e. it lies in the gravitational vertical.’
    • ‘The first fracture occurs in a plane approximately parallel to the snow surface.’
    • ‘To produce good crackling, the raw skin is scored in close parallel lines right through the fat and down to the flesh.’
    • ‘This beetle's other noticeable feature is a set of parallel lines on the front wings that serve as the cover for the hind wings and abdomen.’
    • ‘Fermat also investigated maxima and minima by considering when the tangent to the curve was parallel to the x-axis.’
    • ‘In the other case, the sides of the hexagon are parallel to the sides of the given triangle.’
    • ‘Such side entry eliminates complicating reflections from the other parallel surface of the substrate.’
    • ‘The fact that the loading axis was parallel to the axis of the anchors may result in underestimating the effects of suture-anchor interaction at the eyelet.’
    • ‘Part of the alleyway, which runs parallel to the north side of Manchester Road, remained sealed off.’
    • ‘The most important result in Guidobaldo's treatise was that any set of parallel lines, not parallel to the plane of the picture, will converge to a vanishing point.’
    • ‘In atom lithography, a stream of atoms is focused onto a surface by laser light that runs parallel to the surface.’
    • ‘The lines midway between parallel sides of the hexagon also form a triangle.’
    • ‘Euclid wished to discover whether there existed a simple geometrical proportionality between the apparent size of equal and parallel lines and their distances from the eye.’
    • ‘If we have a uniform grid of parallel lines, unit distance apart and if we drop a needle of length k < 1 on the grid, the probability that the needle falls across a line is 2k/p.’
    • ‘The lateral surface area of a spherical slice cut by two parallel planes is equal to the lateral surface area of the corresponding slice of the circumscribing cylinder.’
    • ‘Von Laue showed that x rays are diffracted in specific directions determined by the distances of separation between the parallel planes of molecules in crystals.’
    • ‘Your feet should be firmly planted on the wall with your toes pointed upward at a line nearly parallel to the surface of the water.’
    side by side, aligned, collateral, equidistant
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    1. 1.1Occurring or existing at the same time or in a similar way; corresponding.
      ‘a parallel universe’
      ‘they shared an apartment in Dallas while establishing parallel careers’
      • ‘NAT King Cole was a prodigious artist with parallel careers: as a great jazz pianist who cut some beautiful sides with heavyweights such as Lester Young, and as a crooner with a voice like soft petals.’
      • ‘He lives in an England which lies in a universe which is parallel to ours - a world where Joshua Wagstaffe discovered aether in 1678.’
      • ‘He also has a parallel career as a cricket writer and has published two anecdotal histories of Indian cricket.’
      • ‘There is also a third source of shared variation: independent parallel mutations, which may be a special problem in species that are very polymorphic.’
      • ‘Although once synonymous with the German New Wave of the early 1970s, Wenders has enjoyed a long parallel career in American cinema and divided his time between Berlin and Hollywood.’
      • ‘Combining elements of live improvisation with beat manipulation, Cinematic Orchestra creates soundtracks for movies that exist in some parallel universe.’
      • ‘The irreducible mind and the body are more like parallel or independent properties that don't causally influence each other.’
      • ‘He won a scholarship to the Royal College of Music, where he studied composition with Vaughan Williams and, by the time the second world war broke out, he had developed a parallel career as a composer and organist.’
      • ‘Perhaps, like me, you went with friends, talked late into the night, argued over theories: parallel universes, time-slippages, identity disorders.’
      • ‘Lovecraft based a parallel Massachusetts on the existing one.’
      • ‘Widdowson's solo writing has prepared him well for his parallel career writing material for other people's TV and radio shows.’
      • ‘Those fabulous, hovering blocks of pure colour and intractable darkness - brooding encounters with the infinite - take the viewer beyond the art work into a parallel universe.’
      • ‘Interestingly, these two currents in the study of US ethnic literatures correspond to a parallel divergence on questions of politics and aesthetics.’
      • ‘The phasic and tonic crayfish claw closer neurons have similar sized somata and parallel dendritic branching.’
      • ‘They see it as a parallel place, possibly existing right alongside their own world.’
      similar, analogous, comparable, corresponding, like, resembling, much the same, of a kind, akin, related, kindred, equivalent, correspondent, homologous, analogical, cognate, coequal, matching, duplicate
      coexisting, coexistent, concurrent
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    2. 1.2Computing Involving the simultaneous performance of operations.
      • ‘This can mean one thread running from an application and a second thread running from an operating system, or parallel threads running from within a single application.’
      • ‘An array of qubits operates as a parallel computer capable of performing a large calculation in one step, and the power grows rapidly with the number of qubits.’
      • ‘A parallel data processing system is provided for increasing the program execution rate of a target machine.’
      • ‘The new system will be used to handle clustered parallel visualization software, display high-resolution images and perform real-time rendering.’
      • ‘A DVD drive doesn't need 150 mb/sec of bandwidth, so parallel ATA performance is good enough.’
    3. 1.3Of or denoting electrical components or circuits connected to common points at each end, rather than one to another in sequence.
      The opposite of series
      • ‘More importantly, parallel connections become far less efficient as traffic rates increase, making serial connections more scalable.’
      • ‘Programming the ButtonBox requires constructing a special parallel cable to connect to it, and then running the programming software.’
      • ‘The utility consists of a cable with a USB connector on one end and a DB25 parallel connector at the other end.’
      • ‘I then went ahead and plugged in all the motherboard connectors such as the power switch, reset switch, etc. and then plugged in all the molex and parallel connectors.’
      • ‘It only offers a parallel connection, which is ideal for those with older PCs but lacks the simplicity of USB - though the setup guide makes installation a breeze.’


  • 1A person or thing that is similar or analogous to another.

    ‘a challenge that has no parallel in peacetime this century’
    • ‘The Upanishads have no parallel in the history of thought.’
    • ‘The relief effort, involving 31 countries and regions, is without parallel.’
    • ‘His knowledge of English football from grassroots upwards is without parallel; ditto his track record of nurturing talent and producing consistently watchable teams.’
    • ‘He was also anxious and imperious in equal measure, and driven to an endless activity of rewriting that has no parallel I can think of among novelists.’
    • ‘When the Soviet Union collapsed and the cold war ended, the United States was left in a position of global privilege, prestige and might that had no parallel in history.’
    • ‘As this booklet pointed out, the position of the princes in the Indian polity ‘afforded no parallel to or analogy with any institution known in history’.’
    • ‘Bessie Smith first recorded in 1923, launching a blues career that would have no parallel during the classic blues era.’
    • ‘The great social shift which was slowly undermining the position of the Established Church in England before 1790 had no parallel in the contemporary Caribbean.’
    • ‘Some of the regulations are bizarre and have no parallel.’
    • ‘His political skills are without parallel in his own country, and abroad mark him as the only equal of Clinton.’
    • ‘There is no doubt that the country house faced a crisis in the twentieth century that has no parallel, at least in the eighteenth and nineteenth centuries.’
    • ‘However, the use of gold heightening in the miniatures finds no parallel in Burne-Jones's panel paintings of the period.’
    • ‘Its rich biodiversity, potential for new natural products and recreational value has no parallel.’
    • ‘It was an industrial disaster without parallel in history.’
    • ‘It's an absolutely extraordinary situation which has no parallel in any other Western democracy.’
    • ‘Pushkin is personally present in Russian culture in a way that has no parallel, for instance, in the posthumous lives of Shakespeare, Dante, or Goethe.’
    counterpart, analogue, equivalent, likeness, correspondent, match, twin, duplicate, equal, coequal, mirror
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    1. 1.1A similarity or comparison.
      ‘he points to a parallel between biological evolution and cognitive development’
      ‘he draws a parallel between personal destiny and social forces’
      • ‘She draws a parallel between the disenfranchised state of women and minorities in the nineteenth century and into the present.’
      • ‘Tacitly she suggests a parallel between the fate of Hong Kong's submitting to a socialist government with the full integration of Britain into the EU.’
      • ‘There is a parallel between the anti-change cries of the ancient Athenian paternalists and the wails of today's ‘anti-globals’.’
      • ‘He also draws a parallel between the struggles for status among nineteenth-century black South Africans and similar movements of the twentieth century.’
      • ‘If I have to draw a parallel between foreigners and Bulgarians, I would say that the foreigners have a better base, both as people and professionally.’
      • ‘Science Friction also draws a parallel between the biogenetic pursuit of outward, bodily perfection and the religious pursuit of inner perfection of the soul through devotion to God and prayer.’
      • ‘There is a similar parallel between the revolution of 1399 which dethroned Richard II and that of 1688 which ended the reign of James II.’
      • ‘Lawrence Rhodes, director of the Juilliard School's Dance Division, draws a parallel between the teaching of choreography and the teaching of dance.’
      • ‘Drawing a parallel between India and China, two of the fastest growing markets in Asia-Pacific, he said compensation levels in China were lower than India.’
      • ‘Would you draw a parallel between the socio-economic development of Bulgaria and Spain in the transition period between totalitarian governing and democracy?’
      • ‘Here, Lemon clearly draws a parallel between the rural folk traditions of China and black Southern culture in the United States.’
      • ‘He tells of his arrival in Rome as a foreigner and his struggle to learn Latin, and then draws a parallel between his linguistic difficulties and the subject of his story, his transformation.’
      • ‘Stephen draws a parallel between someone who would spy while pretending to be a friend, and what Matthew did to Absalom.’
      • ‘Brownell draws a parallel between food and cigarettes.’
      • ‘He draws a parallel between intrusive imagery in trauma and the unexpected visual and auditory imagery that may occur about the deceased.’
      • ‘For purposes of example, he draws a parallel between increase in land values and the rising earnings of a newspaper because of the growth of a community.’
      • ‘If I were to draw a parallel between Richard Sanders' art and a literary style, it would definitely be stream of consciousness.’
      • ‘I would argue that in all three works, Clovio draws a parallel between the Roman artistic canon and religious orthodoxy.’
      • ‘On more than one occasion, Egoyan draws a parallel between what transpired in 1915 Armenia and what happened during the Holocaust.’
      • ‘He drew a parallel between the US city devastated by Hurricane Katrina and the island states which scientists believe are under threat unless the process is halted.’
      similarity, likeness, resemblance, analogy, correspondence, equivalence, correlation
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  • 2Each of the imaginary parallel circles of constant latitude on the earth's surface.

    • ‘By late 1844, London was prepared to settle the Oregon question at the 49th parallel.’
    • ‘North and South Korea are working on projects to fully connect two sets of railways across the demilitarized zone that separates the Korean Peninsula at the 38th parallel.’
    • ‘Central Australia was a formally separate entity from the rest of the Territory, marked by the twentieth parallel of latitude.’
    • ‘Eureka lies on a similar latitude to Rostov close to the 45th parallel.’
    • ‘On October 7, patrols of the U.S.1st Cavalry Division crossed the parallel.’
    • ‘Canada Canada is the world's second largest country, with an area of 9971500 km 2, most of it being north of the 49th parallel of latitude and extending to the high Arctic.’
    grid line
    View synonyms
  • 3Printing
    Two parallel lines (‖) as a reference mark.


  • 1 (of something extending in a line) be side by side with (something extending in a line), always keeping the same distance.

    ‘a big concrete gutter that paralleled the road’
    • ‘For half an hour there were no cars as we accelerated, paralleling the line of the river through fields of rich soil resized to prairie proportions.’
    • ‘Formal pedestrian promenades along either side are gracefully paralleled by double rows of live oak trees.’
    • ‘The run will parallel Lake Michigan, with the start/finish line at Randolph Street and Lake Shore Drive, a short walk from the hotels and convention center.’
    • ‘At Trafalgar, Nelson refused to parallel the enemy fleet in traditional line ahead, but crashed into the French battle line with two columns of ships led by himself and Collingwood.’
    • ‘Brett snatched the ball from Logan and ran, with Logan paralleling him on the other side of the court.’
    • ‘Riverside access ends at the village of Catton and we return on a back road that parallels the Swale.’
    • ‘A railroad track parallels the first base line where diesel engines thunder and fume to haul my father's commuter train to the city.’
    • ‘One whale paralleled us for awhile, then rolled on his side and seemed to stare with his eye.’
    • ‘Access is from the road that parallels the east side of Winnemucca Dry Lake.’
    • ‘Although Bratwurst roughly parallels the highway, you'll not see the road from the forest.’
    • ‘The colours of sky and landscape change gradually as we head back on another route - a road paralleling a brook and a big bald ridge.’
    • ‘About four and a half miles down this road, just as it begins to parallel the glen itself, you'll see a river.’
    • ‘Carlile found the road that roughly paralleled the train's route.’
    • ‘Articulated vehicles must necessarily swing out and into the second lane of M50 traffic in order to execute their turn to parallel the line of traffic into which they merge.’
    • ‘It looked like there was a convergence line ahead paralleling highway 33 on the west side.’
    1. 1.1Be similar or corresponding to (something)
      ‘the lawlessness throughout officialdom was paralleled by an increase in lawlessness on the streets’
      • ‘Ironically, the history of hair removal in Western cultures has closely paralleled a rise in concern over hair loss.’
      • ‘The French army's rise paralleled that of the state it served.’
      • ‘A careful examination of the Deuteronomic history suggests that historical echoes parallel the textual.’
      • ‘In particular, I argue that the mirrored characters parallel the structure of folk and fairy tales in their subversive potential.’
      • ‘Across major phylogenetic comparisons, the evolution of Hox clusters generally parallels the evolution of axial complexity.’
      • ‘Throughout history, the rise of the nonprofit sector has paralleled the rise of democratic societies.’
      • ‘In addition, the severity of the tumor growth appeared to follow a continuum paralleling the loss of the protein.’
      • ‘The expansion in the growth of foreign holdings of US financial assets paralleled the dollar's rise.’
      • ‘Figures show an increase in the number of reported anti-gay attacks, which parallels a similar rise in racist assaults over the last two years.’
      • ‘As quite a few theorists about conspiracy theory have pointed out, the rise of conspiracy theories parallels the rise of the internet.’
      • ‘He relied on the theory of correspondences to explain how gains in the material sphere might parallel those in the celestial.’
      • ‘Eminem's rise paralleled the rise of modern hip-hop as America's dominant musical form.’
      • ‘For unexplained reasons, the incidence of peanut allergy has risen over the past few decades in developed countries, paralleling an increase in asthma and atopic disease.’
      • ‘Their popularity paralleled the rise and fall of press freedom.’
      • ‘It is no coincidence that growth in the repo market has paralleled interest rate derivatives that has followed mortgage debt growth.’
      • ‘These results parallel those of the correlation data presented in Table 5 but may differ slightly due to the reduced sample size.’
      • ‘A variety of companies are now making personal-care products based on more natural, and often organic, ingredients, paralleling the rise of the natural foods movement.’
      • ‘Auto exhaust gases fit the timeline, and their increasing amounts parallel the worldwide rise in coronary heart disease.’
      • ‘This dramatic rise in cases of asthma in the Caribbean parallels the increase in dust flux from Africa to Barbados and Miami.’
      • ‘This rise in discharge rate with hypercapnia paralleled the rise in iEMG activity.’
      equal, match, rival, emulate, touch
      resemble, be similar to, be like, bear a resemblance to
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  • in parallel

    • 1Occurring at the same time and having some connection.

      • ‘It can more easily afford to develop next-generation plant in parallel with older lines.’
      • ‘Thus, it seems that an altered respiratory function develops in parallel with duration of cold exposure.’
      • ‘Mass media and popular culture developed in parallel to the Jazz Age in the West.’
      • ‘In the examples so far discussed, the analysis of a word into its component morphemes takes place in parallel at the phonological and the semantic levels.’
      • ‘There are a number of special insights developed in parallel to the main analysis.’
      1. 1.1(of electrical components or circuits) connected to common points at each end; not in series.
        • ‘Two deep-cycle batteries connected in parallel were used to supply power to the data logger and a total of eight gauges.’
        • ‘We wired a small electric light in parallel with the circuit to the engine heater.’
        • ‘Most of the circuits were in parallel, so one tube flickering caused the others in that circuit to pulse in antiphase.’
        • ‘Here, though, the turbochargers work in series rather than in parallel: a small one close to the engine, a bigger one downstream.’
        • ‘Three thermocouples were connected in parallel to give a mean output.’


Mid 16th century: from French parallèle, via Latin from Greek parallēlos, from para- alongside + allēlos one another.