sex activity vs posterior

sex activity and posterior both are nouns.

Word	Noun	Adjective	Verb	Adverb
sex activity	Yes	No	No	No
posterior	Yes	Yes	No	No

sex activity (noun)	posterior (noun)
activities associated with sexual intercourse	the fleshy part of the human body that you sit on
	a tooth situated at the back of the mouth

sex activity (adjective)	posterior (adjective)
	located at or near or behind a part or near the end of a structure
	coming at a subsequent time or stage