dress hat vs chapeau

dress hat and chapeau both are nouns.

Word	Noun	Adjective	Verb	Adverb
dress hat	Yes	No	No	No
chapeau	Yes	No	No	No

As nouns, chapeau is a hypernym of dress hat; that is, chapeau is a word with a broader meaning than dress hat:

dress hat: a man's hat with a tall crown; usually covered with silk or with beaver fur
chapeau: headdress that protects the head from bad weather; has shaped crown and usually a brim

Other hypernyms of dress hat include hat, lid, man's clothing.

dress hat (noun)	chapeau (noun)
a man's hat with a tall crown; usually covered with silk or with beaver fur	headdress that protects the head from bad weather; has shaped crown and usually a brim