posterior vs subsequent

posterior is a noun but subsequent is not a noun.

Word	Noun	Adjective	Verb	Adverb
posterior	Yes	Yes	No	No
subsequent	No	Yes	No	No

posterior (noun)	subsequent (noun)
the fleshy part of the human body that you sit on
a tooth situated at the back of the mouth

posterior (adjective)	subsequent (adjective)
located at or near or behind a part or near the end of a structure	following in time or order
coming at a subsequent time or stage