coonskin vs coonskin cap

coonskin and coonskin cap both are nouns.

Word	Noun	Adjective	Verb	Adverb
coonskin	Yes	No	No	No
coonskin cap	Yes	No	No	No

As nouns, coonskin and coonskin cap are synonyms defined as:

coonskin and coonskin cap: a raccoon cap with the tail hanging down the back

coonskin (noun)	coonskin cap (noun)
a raccoon cap with the tail hanging down the back	a raccoon cap with the tail hanging down the back