straw hat vs boater

straw hat and boater both are nouns.

Word	Noun	Adjective	Verb	Adverb
straw hat	Yes	No	No	No
boater	Yes	No	No	No

As nouns, straw hat and boater are synonyms defined as:

Other synonyms of straw hat include leghorn, Panama, Panama hat, sailor, skimmer.

straw hat (noun)	boater (noun)
a stiff hat made of straw with a flat crown	a stiff hat made of straw with a flat crown
	someone who drives or rides in a boat