Cassowary kin
I believe the answer is:
rhea
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">cassowary kin</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 rhea that I've seen before include "South American bird resembling the ostrich" , "Grounded bird" , "Moon" , "Greek goddess of fertility - running bird" , "New World flightless bird" .)