Main definitions of arc in English

: arc1ARC2



  • 1A part of the circumference of a circle or other curve.

    • ‘He produced a number of formulas for triangles, two sides of which were straight lines and the third was the arc of a circle.’
    • ‘The question of interest concerns whether, strictly speaking, these arcs form a circle.’
    • ‘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.’
    • ‘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.’
    • ‘He used arcs of great circles instead of arcs of parallel circles on the sphere.’
    • ‘His methods for calculating lengths of arcs of circles were more sophisticated than the Greek methods of Archimedes.’
    • ‘The proof we have examined in detail is one where the outer circumference of the lune is the arc of a semicircle.’
    • ‘These jumps from one number to the next can be visualized as arcs of circles along a number line.’
    • ‘The heavy curve in the figure shows the maximum extent of the cow's range, which consists of several arcs of circles.’
    • ‘All delineations are arcs of a circle, the perfect, complete, easily fractured and reassembled building block of the universe.’
    • ‘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.’
    • ‘This work attempted to solve the problem of constructing a line of the same length as an arc of a circle.’
    curve, bend, bow, arch
    View synonyms
    1. 1.1 A curved shape, or something shaped like a curve.
      ‘the huge arc of the sky’
      • ‘Beyond Corryhabbie Hill on the opposite side of Glen Rinnes, Lochnager and the arc of the Cairngorms form the distant horizon.’
      • ‘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.’
      • ‘In this instance, vinyl stencil lettering took the form of a silver arc of language.’
      • ‘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.’
      • ‘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.’
      • ‘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.’
      • ‘He moved through the crowd schmoozing and smiling, surrounded by an arc of secret service agents, his suit jacket tossed saucily over his shoulder.’
      • ‘Climbing back up, I see an open bay to the west, an arc of cliffs fringed by the grasslands of Ka'u.’
      • ‘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.’
      • ‘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.’
      • ‘Archaeologists have discovered an arc of buried megaliths that once formed part of the great stone circle at Avebury in Wiltshire.’
      • ‘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.’
      • ‘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.’
      • ‘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.’
      • ‘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.’
      • ‘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.’
    2. 1.2 A curving trajectory.
      ‘he swung his flashlight in a wide 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.’
      • ‘She swung the blade in a wide arc, the edge tilted slightly.’
      • ‘The Confederate frigate Halberd swung a wide arc around the freighter's stern and approached her docking port from aft.’
      • ‘‘A decade ago,’ Eldoris murmured, making a wide arc with her arm to accentuate her words.’
      • ‘This allows the blade to swing in a greater arc, producing a wider swathe.’
      • ‘The knight roared, sweeping his ruddy blade out in a wide arc.’
      • ‘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.’
      • ‘He whirled around, his cloak sweeping around in a wide arc.’
      • ‘The man's angular arm plunged toward him in a wide arc.’
      • ‘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.’
      • ‘Inhale slightly more than usual and hold your breath as you lower the weights in a wide arc out to your sides.’
      • ‘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.’
      • ‘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.’
      • ‘On a hard, fast green it is necessary to take a wide arc to reach the jack.’
      • ‘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.’
      • ‘He feels around him, sweeping his arms in wider and wider arcs until he's sure the bag is nearby.’
      • ‘Batman swings in a wide arc and is pulled upward.’
      • ‘I bit my lip as I turned on the tip of my foot, my arms swinging out in wide arcs.’
    3. 1.3Mathematics as modifier Indicating the inverse of a trigonometrical function.
      • ‘Using radian measure explains why the inverse-tangent function is also called the ARCtan function - it returns the arc angle when given a tangent.’
      • ‘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.’
      • ‘The other arc functions, acos, and atan, behave as their more-familiar counterparts.’
  • 2A luminous electrical discharge between two electrodes or other points.

    • ‘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.’
    • ‘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.’
    • ‘The flicker produced by fluorescent lamps is a result of the pulsing of the arc within the lamp.’
    • ‘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.’
    • ‘To improve arc initiation and control the spread of the arc, the electrode should be ground to a point.’
    • ‘Light is given off by the arc and by heated electrodes and base metals.’
    • ‘Small arcs of electricity played over its surface as his eyes danced gleefully.’
    • ‘The heat required in this process is generated by electric arcs struck between carbon electrodes and the metal bath.’
    • ‘In flash welding, the heat is obtained from an arc established between the pieces to be welded by electrical resistance.’
    • ‘Scientists later demonstrated that fullerenes can be conveniently generated by setting up an electric arc between two graphite electrodes.’
    • ‘This path is the glowing area associated with an arc / spark, and is the same phenomenon as lightning, although on a much smaller scale.’
    • ‘When it hit, electrical arcs spider-webbed out from the ship, and a humming buzzed from the field.’
    • ‘It was raining, and Mireles saw a blue electrical arc lighting up the sky near Riverside Drive and Glendale Avenue, he said.’
    • ‘White turned the light switch off, there was a severe electrical arc from the conduit, immediately followed by sparks and flames.’
    • ‘In the bottom of the container there was a reservoir of water, and above it an apparatus caused electrical arcs to crackle.’
    • ‘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.’
    • ‘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.’
    • ‘Kentaro looked up at the pagoda where large arcs of electricity were reaching into the sky like a massive Jacob's Ladder.’
  • 3(in a novel, play, or movie) the development or resolution of the narrative or principal theme.

    ‘his transformation provides the emotional arc of the story’
    • ‘Anyway, using James's formula to calculate Griffey's chance of reaching 756 HRs, we can trace the arc of his career.’
    • ‘However the Season 1 Box Set is broken up into three distinct story arcs over the course of its thirteen episodes.’
    • ‘The movies, hilariously enough, follow an almost identical arc to the equally maligned series.’
    • ‘They are just toying with us at this point in the story arc for this set of characters.’
    • ‘It then would have followed a familiar Canadian arc of being rejected on home turf, only to be discovered down south.’
    • ‘This is probably where the derisive humor begins its arc.’
    • ‘For example, she is giving an extra-ordinary performance, but we feel like we're missing large chunks of her emotional arc.’
    • ‘This imperative, exposed through syntax, pervades the eight poems chosen here to represent Paul Celan's twenty-five-year arc of work.’
    • ‘Plot points of the main arc are sprinkled throughout, typically bookending the standalone story.’
    • ‘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.’
    • ‘The second arc, of course, deals with The Big Questions.’
    • ‘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.’
    • ‘The first two episodes are stand-alone installments, as the overall story arc doesn't begin to reveal itself until later.’
    • ‘There's a built-in arc to the story.’
    • ‘It's fair to say that James Cameron gave Sarah Connor a character arc over the course of the first two Terminator films.’
    • ‘Scher bases his films and drawings on found footage and collage, scripting and shooting additional passages necessary to their generally nonnarrative arc.’
    • ‘Story-wise, this season progressed by taking the dangling paternity results from the previous season and turning them into a major arc.’
    • ‘In order to own the entire arc, you'll need all six volumes.’


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

    ‘the ball arced across the room’
    • ‘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.’
    • ‘She caught it, and in one quick turn the ball was up and arcing towards the basket.’
    • ‘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.’
    • ‘We watched our stones arc into the air, miss the birds by several hundred feet and fall to Earth.’
    • ‘Trees had arced and curved towards the apex, forming great artificial archways, which consisted of more than merely wood and leaves.’
    • ‘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.’
    • ‘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.’
    • ‘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.’
    • ‘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.’
    • ‘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.’
    • ‘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.’
    • ‘I watched cabin cruisers arc through the large triangular confluence, then, my detour done, wandered back for the walk proper.’
    • ‘Cool oases carpet the valley after the gentle Touzlimt Pass, and amazing whorls and swirls of strata arc across the eastern mountains.’
    • ‘Seconds later, a ball arced perhaps five yards from right-to-left before settling in the middle of the fairway.’
    • ‘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.’
    • ‘Then, a little way off, she arcs into an effortless U-turn.’
    • ‘The first shot arced neatly if unspectacularly towards the practice green.’
    curl, curve, swerve, spin, turn
    View synonyms
  • 2usually as noun arcingForm an electric arc.

    ‘check that switches operate properly with no sign of arcing’
    • ‘The plasma contactor system safely grounds the station from this high voltage, protecting it from arcing, which could severely damage its surface.’
    • ‘But these efforts were hampered by failed water pressure, exploding gas meters, arcing power lines and other serious hazards.’
    • ‘Once the circuit breaker was tripped, all sparks, flames and arcing ceased.’
    • ‘Electricity was arcing across a gap of about an inch and a half and triggering a safety cut out.’
    • ‘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.’
    • ‘High impedance leads to heating of the material, arcing to the material under the dispersive electrode, and subsequent burns.’
    • ‘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.’
    • ‘Somewhere an electrical source was arcing out, throwing a harsh glare against cold metal like distant lightning reflecting from storm clouds.’
    • ‘The chafing was so severe that the wires within the bundle had begun arcing and welding themselves to the beam creating a large crater.’


  • minute of arc

  • second of arc


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


  • 1Medicine
    AIDS-related complex.

  • 2American Red Cross.