Real Dictionary

hang up
phrasal verb: If you hang up or you hang up the phone, you end a phone call. If you hang up on someone you are speaking to on the phone, you end the phone call suddenly and unexpectedly.

hang up in American English
to put on a hanger, hook, etc., esp. in the proper place
to suspend by placing on a hook, peg, or hanger

hang up in British English
to put on a hook, hanger, etc
noun: an emotional or psychological preoccupation or problem

hang-up
countable noun: If you have a hang-up about something, you have a feeling of fear, anxiety, or embarrassment about it.

hang-up in American English
a problem or difficulty, esp. one of a personal or emotional nature that a person seems unable to deal with
noun: a preoccupation, fixation, or psychological block; complex

hang-up in British English
noun: an emotional or psychological preoccupation or problem