Fruit; flop (5)
I believe the answer is:
lemon
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">fruit</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I know that lemon is a type of citrus fruit)</span><br/ ><br/ >'<span class="explanation-format__original">flop</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ ></span>
(Other definitions for lemon that I've seen before include "Pulsate" , "Melon (anag)" , "fruit is on offer" , "Fruit-tree" , "Fruit (which is proverbially "the answer")" .)