Label left over ace pair of drums (5)
I believe the answer is:
tabla
'pair of drums' is the definition.
(I've seen this before)
'label left over ace' is the wordplay.
'label' becomes 'tab' (I've seen this before).
'left' becomes 'l' (common abbreviation).
'over' means one lot of letters go next to another (in a down clue, some letters go over others).
'ace' becomes 'a' (abbreviation).
'tab'+'l'+'a'='TABLA'
(Other definitions for tabla that I've seen before include "set of drums" , "Belch" , "Pair of drums used in Indian music" , "Indian musical instrument" , "Indian hand drums" .)