Old apple spray (4)
I believe the answer is:
alar
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">old apple spray</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for alar that I've seen before include "Related to wings" , "Relating to wings" , "using such appendages to fly?" , "chemical spray" , "Relating to a wing" .)