enough vs plenty

enough and plenty both are nouns.

Word	Noun	Adjective	Verb	Adverb
enough	Yes	Yes	No	Yes
plenty	Yes	No	No	Yes

As adverbs, enough and plenty are synonyms defined as:

enough (noun)	plenty (noun)
an adequate quantity; a quantity that is large enough to achieve a purpose	a full supply
	(often followed by `of') a large number or amount or extent

enough (adjective)	plenty (adjective)
sufficient for the purpose

enough (adverb)	plenty (adverb)
as much as necessary	as much as necessary