diurnal vs biology

diurnal is not a noun while biology is a noun.

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

diurnal (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

diurnal (adjective)	biology (adjective)
of or belonging to or active during the day
having a daily cycle or occurring every day