Appendectomy evidence (4)
I believe the answer is:
scar
'appendectomy evidence' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for scar that I've seen before include "Mark left by the healing of injured tissue" , "Disfigure" , "Steep cliff; skin mark" , "fall could possibly be the reason for one" , "Mark, blemish" .)