plenty vs mountain

plenty and mountain both are nouns.

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

As nouns, plenty and mountain are synonyms defined as:

plenty and mountain: (often followed by `of') a large number or amount or extent

plenty (noun)	mountain (noun)
a full supply	a land mass that projects well above its surroundings; higher than a hill
(often followed by `of') a large number or amount or extent	(often followed by `of') a large number or amount or extent

plenty (adverb)	mountain (adverb)
as much as necessary