derby vs plug hat

derby and plug hat both are nouns.

Word	Noun	Adjective	Verb	Adverb
derby	Yes	No	No	No
plug hat	Yes	No	No	No

As nouns, derby and plug hat are synonyms defined as:

derby and plug hat: a felt hat that is round and hard with a narrow brim

Other synonyms of derby include bowler, bowler hat, derby hat.

derby (noun)	plug hat (noun)
a felt hat that is round and hard with a narrow brim	a felt hat that is round and hard with a narrow brim