poke bonnet vs chapeau

poke bonnet and chapeau both are nouns.

Word	Noun	Adjective	Verb	Adverb
poke bonnet	Yes	No	No	No
chapeau	Yes	No	No	No

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

poke bonnet: a hat tied under the chin
chapeau: headdress that protects the head from bad weather; has shaped crown and usually a brim

Other hypernyms of poke bonnet include hat, lid.

poke bonnet (noun)	chapeau (noun)
a hat tied under the chin	headdress that protects the head from bad weather; has shaped crown and usually a brim