electric arc vs arc

electric arc and arc both are nouns.

Word	Noun	Adjective	Verb	Adverb
electric arc	Yes	No	No	No
arc	Yes	No	Yes	No

As nouns, electric arc and arc are synonyms defined as:

electric arc and arc: electrical conduction through a gas in an applied electric field

Other synonyms of electric arc include discharge, electric discharge, spark.

electric arc (noun)	arc (noun)
electrical conduction through a gas in an applied electric field	electrical conduction through a gas in an applied electric field
	a continuous portion of a circle
	something curved in shape

electric arc (verb)	arc (verb)
	form an arch or curve