gift vs gift horse

gift and gift horse both are nouns.

Word	Noun	Adjective	Verb	Adverb
gift	Yes	No	Yes	No
gift horse	Yes	No	No	No

As nouns, gift horse is a hyponym of gift; that is, gift horse is a word with a more specific, narrower meaning than gift:

gift: something acquired without compensation
gift horse: a gift (usually of inferior quality) that should be accepted uncritically

gift (noun)	gift horse (noun)
the act of giving	a gift (usually of inferior quality) that should be accepted uncritically
natural abilities or qualities
something acquired without compensation

gift (verb)	gift horse (verb)
give as a present; make a gift of
give qualities or abilities to