common hop vs common hops

common hop and common hops both are nouns.

Word	Noun	Adjective	Verb	Adverb
common hop	Yes	No	No	No
common hops	Yes	No	No	No

As nouns, common hop and common hops are synonyms defined as:

common hop and common hops: European twining plant whose flowers are used chiefly to flavor malt liquors; cultivated in America

Other synonyms of common hop include bine, European hop, Humulus lupulus.

common hop (noun)	common hops (noun)
European twining plant whose flowers are used chiefly to flavor malt liquors; cultivated in America	European twining plant whose flowers are used chiefly to flavor malt liquors; cultivated in America