To repeat monotonously, like a cuckoo repeats his call.

1. Of, relating to, or resembling the cuckoo
2. Deficient in sense or intelligence; silly

ETYM Old Eng. coccou, cukkow, French coucou, prob. of imitative origin; cf. Latin cuculus, Skr. kukiua, German kuckuk, Dutch koekoek.
Any of numerous European and North American birds having pointed wings and a long tail.
Species of bird, any of about 200 members of the family Cuculidae, especially the Eurasian cuckoo Cuculus canorus, whose name derives from its characteristic call. Somewhat hawklike, it is about 33 cm/1.1 ft long, bluish gray and barred beneath (females sometimes reddish), and has a long, typically rounded tail. Cuckoos feed on insects, including hairy caterpillars that are distasteful to most birds. It is a “brood parasite”, laying its eggs singly, at intervals of about 48 hours, in the nests of small insectivorous birds. As soon as the young cuckoo hatches, it ejects all other young birds or eggs from the nest and is tended by its “foster parents” until fledging. American species hatch and rear their own young.
The North American roadrunner Geococcyx californianus is a member of the cuckoo family.