1) Billing accompaniment 2) Columbine commentary 3) Emit 4) Emulating a pigeon 5) Let loose 6) Let out 7) Making baby noises 8) Making baby or dove noises 9) Rooftop communication 10) Sound from the dovecote 11) Sounding like a dove 12) Speaking lovingly 13) Talking amorously 14) Talking to a baby 15) That is making a soft cry 
• (p. pr. & vb. n.) of Coo
[adj] - that is making a soft cry
adjective that is making a soft cry; `the cooing pigeons`