Pigeon cry (3)
I believe the answer is:
coo
'pigeon cry' is the definition.
'coo' can be an answer for 'cry' (coo is a kind of cry). I also know that 'pigeon' relates to this answer.
This is all the clue.
(Other definitions for coo that I've seen before include "Sound made by dove" , "crumbs" , "Speak lovingly -- cry softly" , "Pigeon noise" , "Make loving sounds -bill and . . ." .)