cuckoo

Etymology

From Middle English cokkou, probably from Old French cucu (whence French coucou); ultimately onomatopoeic of the song of the male Common Cuckoo (Cuculus canorus), perhaps via Latin cucūlus (“cuckoo”). Displaced native Old English ġēac (> modern dialect yek (“cuckoo”)).

noun

1. Any of various birds, of the family Cuculidae, famous for laying its eggs in the nests of other species; but especially a common cuckoo (Cuculus canorus), that has a characteristic two-note call.
2. The sound of that particular bird.
3. The bird-shaped figure found in cuckoo clocks.
4. The cuckoo clock itself.
5. A person who inveigles themselves into a place where they should not be (used especially in the phrase a cuckoo in the nest).
6. (slang) Someone who is crazy.
7. Alternative form of coo-coo (“Barbadian food”)

verb

1. To make the call of a cuckoo.
2. To repeat something incessantly.
3. (UK, law enforcement) To take over the home of a vulnerable person for the purposes of carrying out organized crime in a concealed way.

adj

1. (slang) Crazy; not sane.
   I think I'm going cuckoo!