Fertile desert spot (5)
I believe the answer is:
oasis
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">fertile desert spot</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for oasis that I've seen before include "retreat" , "Green spot; rock group" , "Fertile place like waterhole in desert" , "Safe haven" , "Place of calm in troubled times" .)