Solution for 17 September cryptic crossword clue

Urges to get off drink, we hear (4) – boos

If someone is on stage and not doing well, he or she might be boo'ed off the stage.  Urges therefore = boos

And boos sounds like booze which is slang for alcoholic drink.

This is a "sounds like" clue which was indicated by the use of "we hear" in the clue.