sex activity vs ass

sex activity and ass both are nouns.

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

sex activity (noun)	ass (noun)
activities associated with sexual intercourse	slang for sexual intercourse
	hardy and sure-footed animal smaller and with longer ears than the horse
	the fleshy part of the human body that you sit on
	a pompous fool