# Main definitions of arc in US English:

: arc1ARC2

## arc1

### noun

• 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 proof we have examined in detail is one where the outer circumference of the lune is the arc of a semicircle.’
• ‘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.’
• ‘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.’
• ‘His methods for calculating lengths of arcs of circles were more sophisticated than the Greek methods of Archimedes.’
• ‘These jumps from one number to the next can be visualized as arcs of circles along a number line.’
• ‘The question of interest concerns whether, strictly speaking, these arcs form 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.’
• ‘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.’
• ‘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’
• ‘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.’
• ‘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.’
• ‘A dramatic arc of water is created as four women enjoy a communal bathing session in Son La province, north-western Vietnam.’
• ‘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.’
• ‘He moved through the crowd schmoozing and smiling, surrounded by an arc of secret service agents, his suit jacket tossed saucily over his shoulder.’
• ‘With each swing, she kicks out a beautiful arc of water.’
• ‘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.’
• ‘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.’
• ‘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.’
• ‘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.’
• ‘Beyond Corryhabbie Hill on the opposite side of Glen Rinnes, Lochnager and the arc of the Cairngorms form the distant horizon.’
• ‘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?’
• ‘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.’
• ‘Climbing back up, I see an open bay to the west, an arc of cliffs fringed by the grasslands of Ka'u.’
• ‘Archaeologists have discovered an arc of buried megaliths that once formed part of the great stone circle at Avebury in Wiltshire.’
• ‘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 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.’
2. 1.2 A curving trajectory.
‘he swung his flashlight in a wide arc’
• ‘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.’
• ‘I bit my lip as I turned on the tip of my foot, my arms swinging out in wide arcs.’
• ‘He feels around him, sweeping his arms in wider and wider arcs until he's sure the bag is nearby.’
• ‘The knight roared, sweeping his ruddy blade out in a wide arc.’
• ‘The Confederate frigate Halberd swung a wide arc around the freighter's stern and approached her docking port from aft.’
• ‘Inhale slightly more than usual and hold your breath as you lower the weights in a wide arc out to your sides.’
• ‘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.’
• ‘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.’
• ‘‘A decade ago,’ Eldoris murmured, making a wide arc with her arm to accentuate her words.’
• ‘He whirled around, his cloak sweeping around in a wide arc.’
• ‘The sword came in a low arc before it chopped into the tree.’
• ‘On a hard, fast green it is necessary to take a wide arc to reach the jack.’
• ‘Batman swings in a wide arc and is pulled upward.’
• ‘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.’
• ‘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.’
• ‘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.’
• ‘The man's angular arm plunged toward him 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.’
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.

• ‘Weak arcs of scorching lightning zapped outwards, rapidly fading over the short distance.’
• ‘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.’
• ‘Scientists later demonstrated that fullerenes can be conveniently generated by setting up an electric arc between two graphite electrodes.’
• ‘Small arcs of electricity played over its surface as his eyes danced gleefully.’
• ‘Light is given off by the arc and by heated electrodes and base metals.’
• ‘In the bottom of the container there was a reservoir of water, and above it an apparatus caused electrical arcs to crackle.’
• ‘It was raining, and Mireles saw a blue electrical arc lighting up the sky near Riverside Drive and Glendale Avenue, he said.’
• ‘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.’
• ‘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.’
• ‘In flash welding, the heat is obtained from an arc established between the pieces to be welded by electrical resistance.’
• ‘This is not someone dropping a switch and seeing an arc of electricity.’
• ‘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 it hit, electrical arcs spider-webbed out from the ship, and a humming buzzed from the field.’
• ‘White turned the light switch off, there was a severe electrical arc from the conduit, immediately followed by sparks and flames.’
• ‘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.’
• ‘Kentaro looked up at the pagoda where large arcs of electricity were reaching into the sky like a massive Jacob's Ladder.’
• ‘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.’
• 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’
• ‘They are just toying with us at this point in the story arc for this set of characters.’
• ‘This is probably where the derisive humor begins its arc.’
• ‘This imperative, exposed through syntax, pervades the eight poems chosen here to represent Paul Celan's twenty-five-year arc of work.’
• ‘It's fair to say that James Cameron gave Sarah Connor a character arc over the course of the first two Terminator films.’
• ‘The teenage comedy arc is fully intact: geek is a geek, geek becomes popular, geek faces insurmountable odds, geek triumphs.’
• ‘She gives Gina a great '70 s attitude, though I was never sure where her character arc was going.’
• ‘Story-wise, this season progressed by taking the dangling paternity results from the previous season and turning them into a major arc.’
• ‘It then would have followed a familiar Canadian arc of being rejected on home turf, only to be discovered down south.’
• ‘The second arc, of course, deals with The Big Questions.’
• ‘In order to own the entire arc, you'll need all six volumes.’
• ‘Anyway, using James's formula to calculate Griffey's chance of reaching 756 HRs, we can trace the arc of his career.’
• ‘The movies, hilariously enough, follow an almost identical arc to the equally maligned series.’
• ‘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.’
• ‘For example, she is giving an extra-ordinary performance, but we feel like we're missing large chunks of her emotional arc.’
• ‘Plot points of the main arc are sprinkled throughout, typically bookending the standalone story.’
• ‘However the Season 1 Box Set is broken up into three distinct story arcs over the course of its thirteen episodes.’
• ‘There's a built-in arc to the story.’
• ‘The first two episodes are stand-alone installments, as the overall story arc doesn't begin to reveal itself until later.’
• ‘Today I thus have only the vaguest idea of the story of King David, the basis for the arc of Kings.’

### verb

[no object]
• 1with adverbial of direction Move with a curving trajectory.

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

‘check that switches operate properly with no sign of arcing’
• ‘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.’
• ‘Somewhere an electrical source was arcing out, throwing a harsh glare against cold metal like distant lightning reflecting from storm clouds.’
• ‘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 chafing was so severe that the wires within the bundle had begun arcing and welding themselves to the beam creating a large crater.’
• ‘The plasma contactor system safely grounds the station from this high voltage, protecting it from arcing, which could severely damage its surface.’
• ‘Wires were coated with scale-like insulation materials to prevent the electricity from arcing.’
• ‘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.’
• ‘Electricity was arcing across a gap of about an inch and a half and triggering a safety cut out.’

### Origin

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’.

/ɑrk//ärk/

: arc1ARC2

## ARC2

### abbreviation

• 1Medicine
AIDS-related complex.

• 2American Red Cross.

/ɑrk//ärk/