Pigeon noise (3)
I believe the answer is:
coo
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">pigeon noise</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 coo that I've seen before include "Sound like a dove" , "Make loving sounds -bill and . . ." , "Breathe" , "Surprised expression" , "Gosh!" .)