___ tissue (4)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
scar
'tissue' is the definition.
(I know that scar is a type of tissue)
This is the entire clue.
(Other definitions for scar that I've seen before include "Effect of unpleasant experience" , "Permanent mark left by a wound" , "Sign of wound" , "nine [AL CAPONE] had to face" , "Mark left by healed wound" .)