Balding actor essentially seeks advice about performing operation (4,2,3)
I believe the answer is:
thin on top
'balding' is the definition.
(I've seen this before)
'actor essentially seeks advice about performing operation' is the wordplay.
I cannot quite see how this works, but
'about' could be 'on' and 'on' is found within the answer.
'operation' could be 'op' and 'op' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for thin on top that I've seen before include "Balding (colloq.)" , "with less than full head" , "Going bald" , "Result of losing hair, balding" , "State of advancing baldness" .)