The "A" in WASP (5)
I believe the answer is:
anglo
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">the a in wasp</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for anglo that I've seen before include "Prefix meaning English or British" , "Prefix denoting English" .)