sexual activity vs climax

sexual activity and climax both are nouns.

Word	Noun	Adjective	Verb	Adverb
sexual activity	Yes	No	No	No
climax	Yes	No	Yes	No

sexual activity (noun)	climax (noun)
activities associated with sexual intercourse	the moment of most intense pleasure in sexual intercourse
	the decisive moment in a novel or play
	arrangement of clauses in ascending order of forcefulness
	the highest point of anything conceived of as growing or developing or unfolding
	the most severe stage of a disease

sexual activity (verb)	climax (verb)
	end, especially to reach a final or climactic stage