Indentations (7)
I believe the answer is:
notches
'indentations' is the definition.
(notch is a kind of indentation)
This is all the clue.
(Other definitions for notches that I've seen before include "Nicks" , "Makes small indentation in" , "Small v-shaped cuts" , "V-Shaped cuts or indentations" , "Small indentations found on chest" .)