# arc

> English word · Noun · IPA /ɑːk/ · frequency rank #5,005

## Definitions
1. That part of a circle which a heavenly body appears to pass through as it moves above and below the horizon.
2. A continuous part of the circumference of a circle (circular arc) or of another curve.
3. A curve, in general.
4. A band contained within parallel curves, or something of that shape.
5. A flow of current across an insulating medium; especially a hot, luminous discharge either between two electrodes or as lightning.
6. Ellipsis of story arc.
7. Ellipsis of story arc.
8. A continuous mapping from a real interval (typically [0, 1]) into a space.
9. A directed edge.
10. The three-point line.
11. An arclight.

## Etymology
Etymology tree
Proto-Indo-European *h₂erkʷ-
Proto-Indo-European *h₂erkʷos
Proto-Italic *arkuos
Latin arcus
Old French arcbor.
Middle English ark
English arc
Inherited from Middle English ark, from Old French arc, from Latin arcus (“a bow, arc, arch”), ultimately from Proto-Indo-European *h₂erkʷos (“bow, arrow”). Doublet of arch, arco, and arrow.

## Easily confused with
- **as** (https://plainspell.com/en/vs/arc-vs-as)
- **at** (https://plainspell.com/en/vs/arc-vs-at)
- **aw** (https://plainspell.com/en/vs/arc-vs-aw)
- **AU** (https://plainspell.com/en/vs/arc-vs-au)
- **AZ** (https://plainspell.com/en/vs/arc-vs-az)
- **av** (https://plainspell.com/en/vs/arc-vs-av)
- **ay** (https://plainspell.com/en/vs/arc-vs-ay)
- **ax** (https://plainspell.com/en/vs/arc-vs-ax)
- **are** (https://plainspell.com/en/vs/arc-vs-are)
- **ask** (https://plainspell.com/en/vs/arc-vs-ask)
- **art** (https://plainspell.com/en/vs/arc-vs-art)
- **ass** (https://plainspell.com/en/vs/arc-vs-ass)
- **arm** (https://plainspell.com/en/vs/arc-vs-arm)
- **ate** (https://plainspell.com/en/vs/arc-vs-ate)
- **ash** (https://plainspell.com/en/vs/arc-vs-ash)
- **ave** (https://plainspell.com/en/vs/arc-vs-ave)
- **aye** (https://plainspell.com/en/vs/arc-vs-aye)
- **ATM** (https://plainspell.com/en/vs/arc-vs-atm)
- **awe** (https://plainspell.com/en/vs/arc-vs-awe)
- **axe** (https://plainspell.com/en/vs/arc-vs-axe)

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/arc