White-tailed sea eagle (4)
I believe the answer is:
erne
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">white-tailed sea eagle</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for erne that I've seen before include "Flier" , "Seabird" , "Fish-eating sea eagle" , "Irish lough" , "Marine flyer" .)