sexual activity vs haphazard

sexual activity is a noun but haphazard is not a noun.

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

sexual activity (noun)	haphazard (noun)
activities associated with sexual intercourse

sexual activity (adjective)	haphazard (adjective)
	marked by great carelessness
	dependent upon or characterized by chance

sexual activity (adverb)	haphazard (adverb)
	without care; in a slapdash manner