Desert, leave behind (7)
I believe the answer is:
abandon
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">desert</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >'<span class="explanation-format__original">leave behind</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(abandoning is a kind of leaving behind)</span><br/ ><br/ ></span>
(Other definitions for abandon that I've seen before include "Cast aside" , "Lack of inhibition; desert" , "Total lack of inhibition (often gay?)" , "Forsake, leave behind" , "a complete lack of restraint" .)