Mark or blemish permanently (4)
I believe the answer is:
scar
This clue is a double definition.
'mark' is the first definition.
(mark left by an injury)
'blemish permanently' is the second definition.
(I've seen this in another clue)
(Other definitions for scar that I've seen before include "One left after having wound" , "Old wound - bare cliff" , "Old-wound mark" , "Sign of old injury" , "Stigma" .)