Nick, incision (5)
I believe the answer is:
notch
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">nick</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(both can mean a small cut or impression)</span><br/ ><br/ >'<span class="explanation-format__original">incision</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ ></span>
(Other definitions for notch that I've seen before include "Incision on an edge" , "Snick" , "Nick - incision" , "small score?" , "Mark indented in wood etc" .)