Clam (4)
I believe the answer is:
buck
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">clam</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for buck that I've seen before include "Male rabbit, deer etc" , "may stop here and > be passed" , "profit" , "Spirited male" , "Male hare" .)