sex activity vs stern

sex activity and stern both are nouns.

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

sex activity (noun)	stern (noun)
activities associated with sexual intercourse	the rear part of a ship
	the fleshy part of the human body that you sit on

sex activity (adjective)	stern (adjective)
	severe and unremitting in making demands
	not to be placated or appeased or moved by entreaty
	of a stern or strict bearing or demeanor; forbidding in aspect
	severely simple