hookup vs hook up

hookup is a noun but hook up is not a noun.

Word	Noun	Adjective	Verb	Adverb
hookup	Yes	No	No	No
hook up	No	No	Yes	No

hookup (noun)	hook up (noun)
a system of components assembled together for a particular purpose
a device providing a connection between a power source and a user

hookup (verb)	hook up (verb)
	connect or link