sex activity vs crest

sex activity and crest both are nouns.

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

sex activity (noun)	crest (noun)
activities associated with sexual intercourse	a showy growth of e.g. feathers or skin on the head of a bird or other animal
	(heraldry) in medieval times, an emblem used to decorate a helmet
	the center of a cambered road
	the top line of a hill, mountain, or wave
	the top or extreme point of something (usually a mountain or hill)

sex activity (verb)	crest (verb)
	reach a high point
	lie at the top of