sq ft vs square measure

sq ft and square measure both are nouns.

Word	Noun	Adjective	Verb	Adverb
sq ft	Yes	No	No	No
square measure	Yes	No	No	No

As nouns, square measure is a hypernym of sq ft; that is, square measure is a word with a broader meaning than sq ft:

Other hypernyms of sq ft include area unit.

sq ft (noun)	square measure (noun)
a unit of area equal to one foot by one foot square	a system of units used to measure areas