Use loaf

Also found in: Dictionary, Thesaurus, Legal.

Use your loaf.

  (British & Australian old-fashioned)
if you tell someone to use their loaf, you are telling them in a slightly angry way that they should think more carefully about what they are doing
Usage notes: In Cockney rhyming slang (= an informal kind of language used in parts of London) 'loaf' is short for 'loaf of bread' which means head.
You haven't even switched the thing on. Come on, Jamie, use your loaf!
See It's no good crying over spilt milk, turn to good account, be no good to man or beast
See also: loaf, use