From Longman Dictionary of Contemporary Englishcoocoo1 /kuː/ verb 1 [intransitive]HBB when doves or pigeons coo, they make a low soft cry2 [intransitive, transitive]SAY to make soft quiet sounds, or to speak in a soft quiet way ‘Darling, ’ she cooed. a cooing voice —coo noun [countable] → bill and coo at bill2(3)→ See Verb table
Examples from the Corpus
coo• The baby cooed as I held her.• Other parents feel drained, with little emotional energy to devote to smiling and cooing at a seemingly uninterested child.• We all watched as Alice stopped to coo at two canaries in a silver cage on the porch.• After recovering from an attack of shallow breathing he recovered and one nurse said he was smiling and cooing in his cot.• And, according to the radio, doves were cooing in the Kremlin.• So the guards helped him down, cooing still.• A maid, Nancy Brown, was appointed to wait on her and hairdressers hovered over her cooing their praises.• He spoke of pretty girls cooing to him on college campuses and of assistant coaches questioning his manhood.coocoo2 interjection British English SURPRISEDused to express surprise Coo! That must have cost a lot!From Longman Business DictionaryCOOCOO HUMAN RESOURCESabbreviation for chief operating officer → see under officerOrigin coo (1600-1700) From the sound coo2 (1900-2000) Natural sound 