fearful vs sex activity

fearful is not a noun while sex activity is a noun.

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

fearful (noun)	sex activity (noun)
	activities associated with sexual intercourse

fearful (adjective)	sex activity (adjective)
lacking courage; ignobly timid and faint-hearted
experiencing or showing fear
causing fear or dread or terror
extremely distressing
timid by nature or revealing timidity