coo(n = noun.event) - the sound made by a pigeon;
is a kind of cry
Derived form verb coo₂

1.  coo(v = verb.communication) - speak softly or lovingly; "The mother who held her baby was cooing softly"
is one way to murmur
Sample sentences: Sam and Sue coo

2.  coo(v = verb.communication) - cry softly, as of pigeons;
is one way to emit, let loose, let out, utter
Derived form noun coo₁
Sample sentences: Something ----s

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." [1913 Webster]

2.  To show affection; to act in a loving way. See under Bill, v. i. Byron. [1913 Webster]

coo, n., v., & int.
--n. a soft murmuring sound like that of a dove or pigeon.
--v. (coos, cooed)
1 intr. make the sound of a coo.
2 intr. & tr. talk or say in a soft or amorous voice.
--int. Brit. sl. expressing surprise or incredulity.

Derivative:
cooingly adv.

Etymology:
imit.

VB  cry, roar, bellow, blare, rebellow, growl, snarl, bark, bow-wow, yelp, bay, bay at the moon, yap, yip, yipe, growl, yarr, yawl, snarl, howl, grunt, gruntle, snort, squeak neigh, whinny, bray, mew, mewl, meow, purr, caterwaul, pule, baa, bleat, low, moo, troat, croak, peep, coo, gobble, quack, honk, gaggle, guggle, crow, caw, squawk, screech cackle, cluck, clack, chuck, chuckle, hoot, hoo, chirp, cheep, chirrup, twitter, cuckoo, warble, trill, tweet, pipe, whistle, hum, buzz, hiss, blatter, ratatat.