Long-legged long-necked wading bird (5)
I believe the answer is:
heron
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">long-legged long-necked wading bird</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for heron that I've seen before include "flier" , "Large British wading bird" , "Wader" , "eg Egret" , "Grey or white long-legged wading bird" .)