We don't have synonyms for cukoo yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are cuckoo and cukor.
°Any of various birds, of the family Cuculidae, famous for laying its eggs in the nests of other species; but especially Cuculus canorus that has a characteristic two-note call.
°Any of various birds, of the family Cuculidae, famous for laying its eggs in the nests of other species; but especially Cuculus canorus that has a characteristic two-note call.