Get beaten, having nothing vague (5)
I believe the answer is:
loose
'vague' is the definition.
(I've seen this before)
'get beaten having nothing' is the wordplay.
'get beaten' becomes 'lose' (I've seen this in another clue).
'having' is an insertion indicator.
'nothing' becomes 'O' (O resembles 0).
'lose' enclosing 'o' is 'LOOSE'.
(Other definitions for loose that I've seen before include "Lax or at large" , "Unsecured; dissolute" , "Relaxed; not tethered" , "escaped!" , "Unrestrained" .)