sex activity vs culmination

sex activity and culmination both are nouns.

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

sex activity (noun)	culmination (noun)
activities associated with sexual intercourse	a concluding action
	the decisive moment in a novel or play
	(astronomy) a heavenly body's highest celestial point above an observer's horizon
	a final climactic stage