functional vs pathology

functional is not a noun while pathology is a noun.

Word	Noun	Adjective	Verb	Adverb
functional	No	Yes	No	No
pathology	Yes	No	No	No

functional (noun)	pathology (noun)
	the branch of medical science that studies the causes and nature and effects of diseases
	any deviation from a healthy or normal condition

functional (adjective)	pathology (adjective)
designed for or capable of a particular function or use
involving or affecting function rather than physiology
relating to or based on function especially as opposed to structure
(of e.g. a machine) performing or capable of performing
designed for or adapted to a function or use
fit or ready for use or service