1º_ Name of the letter /q/ . 2º_ 'Cu' is the chemical symbol for copper. 3º_ 'CU' is an acronym for "University Council", "ulcerative colitis", "urban center", . . . 4º_ ' . cu' is the internet domain for Cuba. 5º_ 'c/u' is an abbreviation for "each", "each unit". See cuckoo .