Old head saw parent after work (6)
I believe the answer is:
trepan
'old head saw' is the definition.
'trepan' can be an answer for 'saw' (I've seen this before). I'm not certain of the 'old head' bit.
'parent after work' is the wordplay.
'after work' indicates anagramming the letters (I've seen 'after working' mean this).
'parent' with letters rearranged gives 'TREPAN'.
Can you help me to learn more?
(Other definitions for trepan that I've seen before include "Cranial surgical instrument" , "Surgically create a hole in the skull" , "Make a hole in skull" , "Surgical saw" , "Surgical instrument used to remove sections of bone from the skull" .)