Meaning

noun electrical conduction through a gas in an applied electric field

noun a continuous portion of a circle

noun something curved in shape

originEtymology 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.

Etymology from Wiktionary, CC BY-SA 3.0