coo 
/ˈku:/ verb
coos; cooed; coo·ing /ˈku:/ verb 1 [no obj] : to make the soft sound of a dove or pigeon ; also : to make a similar sound
▪ The baby cooed quietly in her crib. ▪ The baby was making a cooing sound. 2 : to talk in a soft, quiet, and loving way [no obj] ▪ They all cooed over the baby pictures. [+ obj] ▪ “Oh, how sweet,” she cooed.
▪ The baby cooed quietly in her crib. ▪ The baby was making a cooing sound.
— coo noun, plural coos [count]
▪ We listened to the coos of the pigeons.
▪ We listened to the coos of the pigeons.
