Move (wings) up and down (4)
I believe the answer is:
flap
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">move wings up and down</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 flap that I've seen before include "State of agitation" , "Be agitated; hinged piece" , "Wave up and down - panic" , "State of panic" , "Excitement" .)