say it: ahrk
arc is a noun and verb meaning "electrical conduction through a gas in an applied electric field". It carries 4 recorded senses.
electrical conduction through a gas in an applied electric field
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for arc come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.