The definition of a cuckoo is a type of grayish colored European bird that lays its eggs in the nests of other types of birds, the sound that this type of bird makes or is slang for a crazy person.(noun)
An example of cuckoo is the sound made by a bird clock from the Black Forest in Germany.
See cuckoo in Webster's New World College Dictionary
Origin: ME < OFr coucou, cucu, echoic of the bird's cry
See cuckoo in American Heritage Dictionary 4
cuck·oonoun pl. cuck·oos
Origin: Middle English cuccu, of imitative origin.
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