sex activity vs rump

sex activity and rump both are nouns.

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

sex activity (noun)	rump (noun)
activities associated with sexual intercourse	the part of an animal that corresponds to the human buttocks
	the fleshy part of the human body that you sit on
	fleshy hindquarters; behind the loin and above the round