perch vs area unit

perch and area unit both are nouns.

Word	Noun	Adjective	Verb	Adverb
perch	Yes	No	Yes	No
area unit	Yes	No	No	No

As nouns, area unit is a hypernym of perch; that is, area unit is a word with a broader meaning than perch:

Other hypernyms of perch include square measure.

perch (noun)	area unit (noun)
spiny-finned freshwater food and game fishes	a system of units used to measure areas
any of numerous spiny-finned fishes of various families of the order Perciformes
support consisting of a branch or rod that serves as a resting place (especially for a bird)
any of numerous fishes of America and Europe
an elevated place serving as a seat
a linear measure of 16.5 feet
a square rod of land