arrullo (m)
n.
coo
arrullar
v.
lull to sleep; coo
arrullo
= cooing, coo.
Ex: You wait a little and catch your breath and hear the song of the mourning dove, its cooing nearly putting you to sleep.
Ex: The mourning dove (named so because its coo sounds like a mourner at a funeral) is not a very good nest builder.
arrullar
= coo.
Ex: A flock of snow-white doves were flying back and forth across it, and one sat upon the window's ledge and cooed.