area unit vs square measure

area unit and square measure both are nouns.

Word	Noun	Adjective	Verb	Adverb
area unit	Yes	No	No	No
square measure	Yes	No	No	No

As nouns, area unit and square measure are synonyms defined as:

area unit (noun)	square measure (noun)
a system of units used to measure areas	a system of units used to measure areas