biology vs mouthless

biology is a noun but mouthless is not a noun.

Word	Noun	Adjective	Verb	Adverb
biology	Yes	No	No	No
mouthless	No	Yes	No	No

biology (noun)	mouthless (noun)
the science that studies living organisms
all the plant and animal life of a particular region
characteristic life processes and phenomena of living organisms

biology (adjective)	mouthless (adjective)
	having no mouth or mouthlike opening