arc
Pluralarcs
Pluralarcs
- 1A curved line or shape, such as part of the circumference of a circle, or anything that follows such a curve.
A jet of water rose in a glittering arc and splashed into the pool.
The coastline sweeps north in a long arc toward the lighthouse.
UsageOften in an arc: water rose in an arc; the coast sweeps north in a long arc.
Similarcurve, arch, bow, sweep
Note
This general sense sits closest to the root: Latin arcus meant a bow, so an arc is at heart the curve of a drawn bow.
Checked 2 Nov 2026 · 1 fact
- Arc ultimately derives from Latin arcus, meaning a bow. en.wiktionary.org
- 2Short for story arc: how a story or character develops within one work or across several parts of a series.
The villain's redemption arc took three full seasons to play out.
New readers can start with the latest arc without knowing years of backstory.
UsageA word in front often names the thread: the hero's arc, a redemption arc.
Note
The clipped form counts like any noun: a long series is made of several arcs, and the start of each one is a natural door for a newcomer, which is why comics offer arcs as entry points into a story.
Checked 2 Nov 2026 · 1 fact
- Comics publishers present the beginnings of story arcs as entry points for readers. marvel.com
- 3A flow of electric current across an insulating medium, especially a hot, luminous discharge between two electrodes or in the form of lightning.
A loose connection can let an arc form inside the panel and start a fire.
The welder struck an arc between the electrode and the steel plate.
UsageSet phrase: welders strike an arc. Unlike a spark, an arc stays lit.
Note
A spark jumps and is gone; an arc stays lit, because the current heats the gas in the gap into a plasma that goes on conducting by itself. That is why an arc glows so fiercely and runs so hot. Welders strike one to melt steel, and the film-set lamp put the same discharge to work as light.
Checked 31 Oct 2026 · 5 facts
- A spark is transient, whereas an arc is a sustained discharge. technav.ieee.org
- The current heats and ionizes the gas, sustaining a conducting plasma. 'By itself' is accurate as self-sustaining conduction while electrical power continues. technav.ieee.org
- An electric arc produces intense light and heat. stax.strath.ac.uk
- Welders strike electric arcs to melt steel. twi-global.com
- Arc lamps have used electric discharges to illuminate film sets. iatselocal193.com
- 4The three-point line on a basketball court.
He went 5 for 7 from beyond the arc in the second half.
Their center rarely steps out past the arc.
UsageUsually beyond the arc or inside the arc: 5 for 7 from beyond the arc.
Note
Basketball slang names the three-point line after its shape: for most of its length the line curves at a fixed distance from the basket, an arc in the general "curve" meaning.
Checked 2 Nov 2026 · 1 fact
- Most of the three-point line follows a circular arc at a fixed distance from the basket, with straight sections near the corners. jr.nba.com
- 5
- 6A particular period or phase in a person's life.
After the breakup she went into a solo-travel arc and saw six countries in a year.
Honestly, my running arc lasted about three weeks.
Similarphase, period, stage, era
Note
Online talk took the storytelling meaning and turned it on ordinary lives, treating a stretch of your own time as an episode with a theme.
Checked 2 Nov 2026 · 1 fact
- The Internet slang sense referring to a phase of someone's life extends the storytelling sense. en.wiktionary.org
- 7To form an electric arc, with current leaping across a gap between conductors.
High-voltage lines can arc to a nearby tree if branches grow too close.
During the storm the transformer arced, and the whole street went dark.
UsageOften with to or across: power lines can arc to a tree.
Similarspark
- 8In graph theory, an edge that has a direction, running from one vertex to another.
The algorithm assigns a travel time to every arc in the road network.
A one-way street becomes a single arc in the city's graph.
Note
Many graph theorists say arc when direction matters and keep edge for when it does not. Each arc is an ordered pair of vertices: it leaves its tail and enters its head, so the arc from u to v and the arc from v to u are different, like two one-way streets running opposite ways. Directed edge, the longer name, means exactly the same.
Checked 31 Oct 2026 · 4 facts
- An arc is represented by an ordered pair of vertices. cs.rochester.edu
- An arc goes from its tail to its head. en.wikipedia.org
- Reversing the direction between two distinct vertices gives a different arc. en.wikipedia.org
- An arc is a directed edge. cs.rochester.edu
Less common meanings
- 9To shape something into an arc, or to hold it in a curved position.
The gymnast arced her body backward until her palms touched the mat.
Gardeners arc thin willow rods over the bed to hold up a net.
UsageFor a back or body, arch is the more usual verb: arch your back.
Oppositestraighten
Note
Here the curve is put into something by someone else; in the "move in a curve" sense the thing curves by itself. Watch the ending: arced and arcing are usual, arcked and arcking rare, and James Baldwin, in Go Tell It on the Mountain (1953), writes a mother's hands arked before her.
Checked 31 Oct 2026 · 2 facts
- James Baldwin wrote Go Tell It on the Mountain, first published in 1953. penguinrandomhouse.com
- Baldwin describes a mother's hands as 'arked before her' in the novel's narration. en.wiktionary.org
- 10In filmmaking, an arc light: a powerful lamp whose light comes from an electric arc.
The gaffer swung a second arc into place for the night battle scene.
Each arc needed an operator to keep its carbons trimmed through the take.
Note
On a film set the arc was usually a carbon arc, a lamp whose light burns between two carbon rods. In the 2012 revised edition of Kris Malkiewicz's Film Lighting, a book built on interviews with cinematographers and gaffers, the old carbon arcs are called the backbone of film lighting and, for all practical purposes, no longer used, so the word now belongs mostly to the history of the craft and to talk about older productions.
- 11The part of a circle that a celestial body appears to travel through as it moves above and below the horizon.
In winter the sun travels a low arc and sets early in the afternoon.
Near the equator, the sun's arc carries it almost straight overhead at noon.
Note
Astronomers split this circle at the horizon. The part above is the diurnal arc, traced while the sun or a star is in view; the part below is the nocturnal arc. How the two compare depends on the observer's latitude and the body's declination, and that balance is why days lengthen and shorten through the year: a winter sun rides a short, low arc.
Checked 31 Oct 2026 · 6 facts
- The horizon divides the apparent daily circle into visible and invisible portions. ebooks.inflibnet.ac.in
- The diurnal arc is the portion traced above the horizon, between rising and setting. gutenberg.org
- The nocturnal arc is the portion below the horizon, between setting and rising. gutenberg.org
- The relative extents of these arcs depend on latitude and declination. spider.seds.org
- Seasonal changes in the Sun's above-horizon path correspond to changes in daylight duration. pwg.gsfc.nasa.gov
- The winter Sun follows a shorter, lower path across the sky. aa.usno.navy.mil
- 12A continuous map from an interval of the real numbers, typically [0, 1], into a space.
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Origin
The chain starts with Proto-Indo-European *h₂erkʷos, meaning "bow, arrow," which led to Latin arcus, meaning "a bow, arc, arch," and then to Old French arc. English inherited arc from the Middle English form ark. Arc, arch, arco, and arrow are doublets.