silk hat vs dress hat

silk hat and dress hat both are nouns.

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

As nouns, silk hat and dress hat are synonyms defined as:

silk hat and dress hat: a man's hat with a tall crown; usually covered with silk or with beaver fur

Other synonyms of silk hat include beaver, high hat, opera hat, stovepipe, top hat, topper.

silk hat (noun)	dress hat (noun)
a man's hat with a tall crown; usually covered with silk or with beaver fur	a man's hat with a tall crown; usually covered with silk or with beaver fur