plenty vs plenteousness

plenty and plenteousness both are nouns.

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

As nouns, plenty and plenteousness are synonyms defined as:

Other synonyms of plenty include plenitude, plentifulness, plentitude.

plenty (noun)	plenteousness (noun)
a full supply	a full supply
(often followed by `of') a large number or amount or extent

plenty (adverb)	plenteousness (adverb)
as much as necessary