DICT.TW Dictionary Taiwan

 coo /ˈku/
 (v.)[鴿等] 鴣鴣地叫;唧唧地講情話

 Coo v. i. [imp. & p. p. Cooed p. pr. & vb. n. Cooing.]
 1. To make a low repeated cry or sound, like the characteristic note of pigeons or doves.
 The stockdove only through the forest cooes,
 Mournfully hoarse.   --Thomson.
 2. To show affection; to act in a loving way. See under Bill, v. i. “Billing or cooing.”
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 coo
      n : the sound made by a pigeon
      v 1: speak softly or lovingly; "The mother who held her baby was
           cooing softly"
      2: cry softly, as of pigeons