Jump To:

• arc
  arc

  noun

  any unbroken part of the circumference of a circle or other curved line.
• ARC
  ARC

  noun

  AIDS-related complex.

arc

¹ American  

[ahrk] / ɑrk /

noun

1. Geometry. any unbroken part of the circumference of a circle or other curved line.

2. Also called electric arc.  Electricity. a luminous bridge formed in a gap between two electrodes.

3. Astronomy. the part of a circle representing the apparent course of a heavenly body.

4. anything bow-shaped.

---

verb (used without object)

arced, arcked, arcing, arcking

1. to form an electric arc.

2. to move in a curve suggestive of an arc.

ARC ² American  

[ahrk] / ɑrk /

noun

1. Pathology. AIDS-related complex.

---

ARC ³ American  

Or A.R.C.

abbreviation

1. American Red Cross.

---

arc ¹ British  

/ ɑːk /

noun

1. something curved in shape

2. part of an unbroken curved line

3. a luminous discharge that occurs when an electric current flows between two electrodes or any other two surfaces separated by a small gap and a high potential difference

4. astronomy a circular section of the apparent path of a celestial body

5. maths a section of a curve, graph, or geometric figure

---

verb

1. (intr) to form an arc

prefix

1. maths specifying an inverse trigonometric function: usually written arcsin , arctan , arcsec , etc, or sometimes sin–1 , tan–1 , sec–1 , etc

ARC ² British  

abbreviation

1. AIDS-related complex: an early condition in which a person infected with the AIDS virus may suffer from such mild symptoms as loss of weight, fever, etc

---

arc Scientific  

/ ärk /

1. A segment of a circle.

2. See electric arc

---

Etymology

Origin of arc

1350–1400; Middle English ark < Latin arcus bow, arch, curve

Explanation

An arc is a curve. You can describe the bend of a rainbow as an arc. In math, an arc is one section of a circle, but in life you can use the word to mean any curved shape, like the arc of a ballerina's arm or the graceful arc of a flowering vine over a trellis. In the 14th century, arc first meant the movement of the sun in the sky, from the Old French arc, "bow or arch," and the Latin root arcus, also "bow or arch."

Example Sentences

The new electric arc furnace was hoped to be up and running by the end of 2027, replacing the traditional blast furnaces which closed two years ago with the loss of 2,000 jobs.

From BBC • Jun. 7, 2026

The arc of the transaction was clear, completed, and visible at the pump.

From Slate • Jun. 6, 2026

The arc of history today bends not towards cooperation, but competition.

From MarketWatch • May 31, 2026

Then they called in Season 3 and that was when they said, “OK, we’re gonna do a little arc; we want this to flesh this character out.”

From Los Angeles Times • May 28, 2026

He shot his two-hand set in a soft, spinning arc that, when true, snapped through the net in a swishing voice that is the purest music of the game.

From "The Great Santini" by Pat Conroy

Related Words

• arch