cooing

from The Collaborative International Dictionary of English v.0.48

Coo \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.
      [1913 Webster]

            The stockdove only through the forest cooes,
            Mournfully hoarse.                    --Thomson.
      [1913 Webster]

   2. To show affection; to act in a loving way. See under
      {Bill}, v. i. "Billing or cooing." --Byron.
      [1913 Webster] Cooey

from The Collaborative International Dictionary of English v.0.48

cooing \cooing\ adj. [pr. Participle of verb {coo} (definition
   2)]
   emitting a cry like that of a dove; as, The cooing pigeons.
   [WordNet 1.5]