COO

[verb] he/she/it coos, cooing, past cooed - (esp. of some types of bird, such as doves and pigeons) to make a low soft call, or (of people) to speak in a soft, gentle and loving wayOutside we heard the doves cooing. [I]The baby lay in his cot, cooing and gurgling. [I]It's sickening the way she coos over those cats of hers. [I]"How wonderful to see you again, darling," she cooed. [+ speech]