free-living vs biology

free-living is not a noun while biology is a noun.

Word	Noun	Adjective	Verb	Adverb
free-living	No	Yes	No	No
biology	Yes	No	No	No

free-living (noun)	biology (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

free-living (adjective)	biology (adjective)
not parasitic on another organism