Let, permit (5)
I believe the answer is:
allow
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">let</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >'<span class="explanation-format__original">permit</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ ></span>
(Other definitions for allow that I've seen before include "Acknowledge - concede" , "Permit, let happen" , "Tolerate" , "OK" , "Permit or concede" .)