hookup (Noun) — A device providing a connection between a power source and a user. ex. "some campsites have electrical hookups for trailers"
hookup (Noun) — A system of components assembled together for a particular purpose.
hookup (Verb) — Connect or link. ex. "hook up the houses to the gas supply line" ex. "Hook up the components of the new sound system"
hookup (Verb) — (hook up with) meet up or form an association with someone.
hookup (Verb) — (hook up with) have a sexual encounter with someone.