flattop vs warship

flattop and warship both are nouns.

Word	Noun	Adjective	Verb	Adverb
flattop	Yes	No	No	No
warship	Yes	No	No	No

As nouns, warship is a hypernym of flattop; that is, warship is a word with a broader meaning than flattop:

flattop: a large warship that carries planes and has a long flat deck for takeoffs and landings
warship: a government ship that is available for waging war

Other hypernyms of flattop include combat ship, war vessel.

flattop (noun)	warship (noun)
a large warship that carries planes and has a long flat deck for takeoffs and landings	a government ship that is available for waging war
a closely cropped haircut; usually for men or boys