cork vs bottle cork

cork and bottle cork both are nouns.

Word	Noun	Adjective	Verb	Adverb
cork	Yes	No	Yes	No
bottle cork	Yes	No	No	No

As nouns, cork and bottle cork are synonyms defined as:

cork and bottle cork: the plug in the mouth of a bottle (especially a wine bottle)

cork (noun)	bottle cork (noun)
the plug in the mouth of a bottle (especially a wine bottle)	the plug in the mouth of a bottle (especially a wine bottle)
a small float usually made of cork; attached to a fishing line
outer bark of the cork oak; used for stoppers for bottles etc.
(botany) outer tissue of bark; a protective layer of dead cells

cork (verb)	bottle cork (verb)
stuff with cork
close a bottle with a cork