sex vs erection

sex and erection both are nouns.

Word	Noun	Adjective	Verb	Adverb
sex	Yes	No	Yes	No
erection	Yes	No	No	No

sex (noun)	erection (noun)
activities associated with sexual intercourse	the act of building or putting up
the properties that distinguish organisms on the basis of their reproductive roles	a structure that has been erected
all of the feelings resulting from the urge to gratify sexual impulses	an erect penis
either of the two categories (male or female) into which most organisms are divided

sex (verb)	erection (verb)
tell the sex (of young chickens)
to evoke sexual feelings