monocotyledonous vs plant life

monocotyledonous is not a noun while plant life is a noun.

Word	Noun	Adjective	Verb	Adverb
monocotyledonous	No	Yes	No	No
plant life	Yes	No	No	No

monocotyledonous (noun)	plant life (noun)
	(botany) a living organism lacking the power of locomotion

monocotyledonous (adjective)	plant life (adjective)
(of a flowering plant) having a single cotyledon in the seed as in grasses and lilies