Bloody stupid former pupil (3,3)
I believe the answer is:
old boy
'former pupil' is the definition.
(I've seen this before)
'bloody stupid' is the wordplay.
'stupid' indicates anagramming the letters (in a stupid order).
'bloody' is an anagram of 'OLD BOY'.
(Other definitions for old boy that I've seen before include "Former member of a school" , "Former pupil - kind of network" , "Male ex-pupil" , "Mate" , "Male former pupil" .)