wiper arm vs wiper

wiper arm and wiper both are nouns.

Word	Noun	Adjective	Verb	Adverb
wiper arm	Yes	No	No	No
wiper	Yes	No	No	No

As nouns, wiper arm and wiper are synonyms defined as:

wiper arm and wiper: contact consisting of a conducting arm that rotates over a series of fixed contacts and comes to rest on an outlet

Other synonyms of wiper arm include contact arm.

wiper arm (noun)	wiper (noun)
contact consisting of a conducting arm that rotates over a series of fixed contacts and comes to rest on an outlet	a mechanical device that cleans the windshield
	contact consisting of a conducting arm that rotates over a series of fixed contacts and comes to rest on an outlet
	a worker who wipes