Main definitions of arc in English

: arc1ARC2



  • 1A part of a curve, especially a part of the circumference of a circle.

    ‘the point where a tangential line touches the arc of a circle’
    • ‘He used arcs of great circles instead of arcs of parallel circles on the sphere.’
    • ‘He produced a number of formulas for triangles, two sides of which were straight lines and the third was the arc of a circle.’
    • ‘All delineations are arcs of a circle, the perfect, complete, easily fractured and reassembled building block of the universe.’
    • ‘The heavy curve in the figure shows the maximum extent of the cow's range, which consists of several arcs of circles.’
    • ‘These jumps from one number to the next can be visualized as arcs of circles along a number line.’
    • ‘The proof we have examined in detail is one where the outer circumference of the lune is the arc of a semicircle.’
    • ‘The third part of Mathematical exercises was on the Riccati differential equation while the final part was on a geometry question concerning figures bounded by two arcs of a circle.’
    • ‘The construction was rightly criticised as requiring a knowledge of the ratio of a line and an arc of a circle, so one assumed as known the property required to square the circle in the first place.’
    • ‘His methods for calculating lengths of arcs of circles were more sophisticated than the Greek methods of Archimedes.’
    • ‘Draw three arcs of circles, with each arc having as its center one of the triangle's corners and as its endpoints the other two corners.’
    • ‘This work attempted to solve the problem of constructing a line of the same length as an arc of a circle.’
    • ‘The question of interest concerns whether, strictly speaking, these arcs form a circle.’
    curve, bend, bow, arch
    View synonyms
    1. 1.1 A shape or structure resembling an arc.
      ‘the huge arc of the sky’
      • ‘From the top of a bluff on a clear day, with the sun melting the tarmac and baking my thighs, the deep-blue arc of the horizon looks like the edge of the earth.’
      • ‘The air had a hallucinatory clarity tonight with the bank towers etched against the sky and a surreal arc of sprinklers tending the fields below.’
      • ‘A dramatic arc of water is created as four women enjoy a communal bathing session in Son La province, north-western Vietnam.’
      • ‘On a clear day you can see Ben Nevis in the west and Buchan Ness in the east and beyond Corryhabbie Hill on the opposite side of Glen Rinnes Lochnager and the arc of the Cairngorms form the distant horizon.’
      • ‘In this instance, vinyl stencil lettering took the form of a silver arc of language.’
      • ‘Climbing back up, I see an open bay to the west, an arc of cliffs fringed by the grasslands of Ka'u.’
      • ‘From the outside it sits neatly in the arc of beautiful townhouse mansions with the fluttering Union Jack over the discreet entrance - the only clue that it is a hotel.’
      • ‘As I got to the mill I took my last few pictures and then, as though to say goodbye, the clouds parted just a little and spat out a brilliant arc of sunshine - the first rays of the morning.’
      • ‘The fury of the thundering, cascading water churned up a spray that covered the surrounding forests in a veil of mist and created a rainbow that framed the gorge in an arc of spectacular colours.’
      • ‘Trenna observed the way the cavern was shaped: there was a large arc of rock that concealed one half of the cavern from the other.’
      • ‘His version of Château Lafite follows the original French blueprints but adds two extra floors, and has the building's two wings linked by an arc of Romanesque columns.’
      • ‘He moved through the crowd schmoozing and smiling, surrounded by an arc of secret service agents, his suit jacket tossed saucily over his shoulder.’
      • ‘How many directors dare tell any diva that the first thing they want her to do, as she makes her grand entrance, is dip her head in a bucket and throw back her hair, spraying an arc of water across the stage?’
      • ‘With each swing, she kicks out a beautiful arc of water.’
      • ‘Beyond Corryhabbie Hill on the opposite side of Glen Rinnes, Lochnager and the arc of the Cairngorms form the distant horizon.’
      • ‘The arc of the cloudless sky gives the impression that the whole world is enclosed in a dome and a bird is singing in a nearby tree.’
      • ‘She walked through the entrance, which was a huge arc of blooming roses, and at once was overwhelmed with the beauty and the smell of the roses.’
      • ‘Archaeologists have discovered an arc of buried megaliths that once formed part of the great stone circle at Avebury in Wiltshire.’
    2. 1.2 A curving trajectory.
      ‘he swung his torch in a wide arc’
      • ‘‘A decade ago,’ Eldoris murmured, making a wide arc with her arm to accentuate her words.’
      • ‘Right now, she was employing another of her favourite gestures - sweeping her arm in a wide arc above her head and clicking her fingers so hard it must have hurt.’
      • ‘He whirled around, his cloak sweeping around in a wide arc.’
      • ‘Inhale slightly more than usual and hold your breath as you lower the weights in a wide arc out to your sides.’
      • ‘On a hard, fast green it is necessary to take a wide arc to reach the jack.’
      • ‘The knight roared, sweeping his ruddy blade out in a wide arc.’
      • ‘This allows the blade to swing in a greater arc, producing a wider swathe.’
      • ‘She swung the blade in a wide arc, the edge tilted slightly.’
      • ‘The sword came in a low arc before it chopped into the tree.’
      • ‘Start with the dumbbells at arm's length above your chest and lower them in a wide arc out to your sides until you feel a stretch in your chest.’
      • ‘The man's angular arm plunged toward him in a wide arc.’
      • ‘But I made it safely through the bracken and out the other side, and cut a wide arc back towards the car to continue my journey through the fields and flowers and trees.’
      • ‘Batman swings in a wide arc and is pulled upward.’
      • ‘He feels around him, sweeping his arms in wider and wider arcs until he's sure the bag is nearby.’
      • ‘The Confederate frigate Halberd swung a wide arc around the freighter's stern and approached her docking port from aft.’
      • ‘I bit my lip as I turned on the tip of my foot, my arms swinging out in wide arcs.’
      • ‘The tadpoles can also turn in much wider arcs, which they do spontaneously, when they initiate swimming from rest, and in the course of normal locomotion.’
      • ‘One end of the upper stone was fixed to a pivot and both stones were ‘dressed’ with small diagonal grooves which crossed each other at an angle as the upper stone swept across the lower in an arc.’
      • ‘At this moment Nukite awoke from his deep slumber, his eyes closed in the early morning sunlight he rose slowly to his feet, stretching his arms in a wide arc as he did so.’
    3. 1.3Mathematics as modifier Indicating the inverse of a trigonometrical function.
      • ‘If we use an angle h, the arc length will be krh, where k is a constant that depends on the units of angle you use.’
      • ‘Using radian measure explains why the inverse-tangent function is also called the ARCtan function - it returns the arc angle when given a tangent.’
      • ‘The other arc functions, acos, and atan, behave as their more-familiar counterparts.’
  • 2A luminous electrical discharge between two electrodes or other points.

    ‘modern welding generators are designed so that there is a high voltage for striking the arc’
    • ‘White turned the light switch off, there was a severe electrical arc from the conduit, immediately followed by sparks and flames.’
    • ‘In flash welding, the heat is obtained from an arc established between the pieces to be welded by electrical resistance.’
    • ‘When it hit, electrical arcs spider-webbed out from the ship, and a humming buzzed from the field.’
    • ‘I recall seeing a photo in Scientific American of the arc from a large Tesla Coil being guided in a straight line by a laser pulse.’
    • ‘To improve arc initiation and control the spread of the arc, the electrode should be ground to a point.’
    • ‘This path is the glowing area associated with an arc / spark, and is the same phenomenon as lightning, although on a much smaller scale.’
    • ‘Some two hours later a fire broke out in the Commanding Officer's cabin and electrical space, caused by an arc in the main power cables that ran through the area which had become swamped by water.’
    • ‘As powerful electric arcs leap from welding rod to the metal, they sometimes follow unpredictable, lightning-like paths, leading to sloppy welds and splattered metal.’
    • ‘Weak arcs of scorching lightning zapped outwards, rapidly fading over the short distance.’
    • ‘It was raining, and Mireles saw a blue electrical arc lighting up the sky near Riverside Drive and Glendale Avenue, he said.’
    • ‘Small arcs of electricity played over its surface as his eyes danced gleefully.’
    • ‘Kentaro looked up at the pagoda where large arcs of electricity were reaching into the sky like a massive Jacob's Ladder.’
    • ‘The flicker produced by fluorescent lamps is a result of the pulsing of the arc within the lamp.’
    • ‘The heat required in this process is generated by electric arcs struck between carbon electrodes and the metal bath.’
    • ‘When calibrated to be in tune with the planet's resonance, it created what is still the largest man-made electrical surge ever, an arc over 130 feet long.’
    • ‘This is not someone dropping a switch and seeing an arc of electricity.’
    • ‘Considering all the above factors an arc or spark from a broken wire is most likely to be responsible for a fire on this type of machine and, as I understand it, this reflects industry experience.’
    • ‘In the bottom of the container there was a reservoir of water, and above it an apparatus caused electrical arcs to crackle.’
    • ‘Light is given off by the arc and by heated electrodes and base metals.’
    • ‘Scientists later demonstrated that fullerenes can be conveniently generated by setting up an electric arc between two graphite electrodes.’
  • 3(in a novel, play, or film) the development or resolution of the narrative or principal theme.

    ‘his transformation provides the emotional arc of the story’
    • ‘For example, she is giving an extra-ordinary performance, but we feel like we're missing large chunks of her emotional arc.’
    • ‘Story-wise, this season progressed by taking the dangling paternity results from the previous season and turning them into a major arc.’
    • ‘The first two episodes are stand-alone installments, as the overall story arc doesn't begin to reveal itself until later.’
    • ‘This imperative, exposed through syntax, pervades the eight poems chosen here to represent Paul Celan's twenty-five-year arc of work.’
    • ‘The teenage comedy arc is fully intact: geek is a geek, geek becomes popular, geek faces insurmountable odds, geek triumphs.’
    • ‘Today I thus have only the vaguest idea of the story of King David, the basis for the arc of Kings.’
    • ‘This is probably where the derisive humor begins its arc.’
    • ‘The movies, hilariously enough, follow an almost identical arc to the equally maligned series.’
    • ‘Plot points of the main arc are sprinkled throughout, typically bookending the standalone story.’
    • ‘Anyway, using James's formula to calculate Griffey's chance of reaching 756 HRs, we can trace the arc of his career.’
    • ‘It's fair to say that James Cameron gave Sarah Connor a character arc over the course of the first two Terminator films.’
    • ‘They are just toying with us at this point in the story arc for this set of characters.’
    • ‘In order to own the entire arc, you'll need all six volumes.’
    • ‘However the Season 1 Box Set is broken up into three distinct story arcs over the course of its thirteen episodes.’
    • ‘The second arc, of course, deals with The Big Questions.’
    • ‘There's a built-in arc to the story.’
    • ‘Scher bases his films and drawings on found footage and collage, scripting and shooting additional passages necessary to their generally nonnarrative arc.’
    • ‘Apart from the change in protagonist, the story arc seems to be much the same.’
    • ‘She gives Gina a great '70 s attitude, though I was never sure where her character arc was going.’
    • ‘It then would have followed a familiar Canadian arc of being rejected on home turf, only to be discovered down south.’


  • 1with adverbial of direction Move with a curving trajectory.

    ‘the ball arced across the room’
    • ‘The first shot arced neatly if unspectacularly towards the practice green.’
    • ‘Time slowed as the ball arced across Alan Main in the Gretna goal but dropped in front of Derek Townsley, the home centre-half, who hoofed it beyond peril.’
    • ‘Seconds later, a ball arced perhaps five yards from right-to-left before settling in the middle of the fairway.’
    • ‘We watched our stones arc into the air, miss the birds by several hundred feet and fall to Earth.’
    • ‘If everyone's eyes are up on the ball as it arcs to the basket, you can be sure the offense is cutting around the defense to get better position for rebounds.’
    • ‘Up at the lagoon of São André, returning late in the afternoon from a long walk through the dunes, I saw a girl dive from a canoe, a solitary figure that arced gracefully into the sun-silvered water with hardly a splash.’
    • ‘Cool oases carpet the valley after the gentle Touzlimt Pass, and amazing whorls and swirls of strata arc across the eastern mountains.’
    • ‘The ball arced through the six-yard area and passed just in front of the incoming attackers and defenders before beating Van der Sar at his far post.’
    • ‘Walt Whitman dreams of the first jumpshot he will take, the ball arcing clumsily from his fingers, striking the rim so hard that it sparks.’
    • ‘I watched cabin cruisers arc through the large triangular confluence, then, my detour done, wandered back for the walk proper.’
    • ‘Trees had arced and curved towards the apex, forming great artificial archways, which consisted of more than merely wood and leaves.’
    • ‘Just then the volume leaped to a roar, and the camera panned sharply upward; Henderson spotted the ball arcing high above the stadium, a brilliant streak against the grainy sky.’
    • ‘Then, a little way off, she arcs into an effortless U-turn.’
    • ‘A large dugong and calf had just surfaced for air and I turned round in time to watch their rounded torsos arc in unison and with a swirl of their tails, they disappeared.’
    • ‘She caught it, and in one quick turn the ball was up and arcing towards the basket.’
    • ‘Another half mile, and with an eye on the weather, and tiny twinges in rusty legs, we took a convenient track that arced down to cross the valley to fords of flat sandstone.’
    • ‘Later, when the Square of Pegasus is high enough in the east, one can follow the curve of stars arcing away from its northeast corner.’
    curl, curve, swerve, spin, turn
    View synonyms
  • 2usually as noun arcingForm an electric arc.

    ‘check that switches operate properly with no sign of arcing’
    • ‘This much mental electricity should be able to run a small city, but instead I'm more like a cut power line, arcing and sparking spasmodically.’
    • ‘Once the circuit breaker was tripped, all sparks, flames and arcing ceased.’
    • ‘The chafing was so severe that the wires within the bundle had begun arcing and welding themselves to the beam creating a large crater.’
    • ‘Somewhere an electrical source was arcing out, throwing a harsh glare against cold metal like distant lightning reflecting from storm clouds.’
    • ‘High impedance leads to heating of the material, arcing to the material under the dispersive electrode, and subsequent burns.’
    • ‘Electricity was arcing across a gap of about an inch and a half and triggering a safety cut out.’
    • ‘But these efforts were hampered by failed water pressure, exploding gas meters, arcing power lines and other serious hazards.’
    • ‘Wires were coated with scale-like insulation materials to prevent the electricity from arcing.’
    • ‘A titanium charge is placed in the crucible with granular calcium fluoride added to act as an electrical insulator between the titanium and the crucible to prevent arcing and crucible damage.’
    • ‘The plasma contactor system safely grounds the station from this high voltage, protecting it from arcing, which could severely damage its surface.’


Late Middle English (denoting the path of a celestial object, especially the sun, from horizon to horizon): via Old French from Latin arcus ‘bow, curve’.




Main definitions of arc in English

: arc1ARC2


  • 1historical (in the UK) Agricultural Research Council.

  • 2Medicine
    AIDS-related complex.