[cuck.oo] n, pl cuckoos [ME cuccu, of imit. origin] (13c) 1: a largely grayish brown European bird (Cuculus canorus) that is a parasite given to laying its eggs in the nests of other birds which hatch them and rear the offspring; broadly: any of a large family (Cuculidae of the order Cuculiformes) to which this bird belongs
2: the call of the cuckoo
3: a silly or slightly crackbrained person
[2]cuckoo vt (1648): to repeat monotonously as a cuckoo does its call [3]cuckoo adj (1627) 1: of, relating to, or resembling the cuckoo
2: deficient in sense or intelligence: silly