Arrow notch (4)
I believe the answer is:
nock
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">arrow notch</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for nock that I've seen before include "Score" , "Archer's notch" , "something groovy" .)