Bud's buddy (3)
I believe the answer is:
lou
'bud's buddy' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for lou that I've seen before include "-- Costello, Abbott's partner" , "Male or female" , "-- Reed, rock musician" , "--- Costello, US comic" , "man" .)