ニ Meanings Noun 4th (in a sequence denoted by the iroha system); d; iv See also: いろは順 (いろはじゅん). D (note) (used mainly in key names) Words containing ニ ニ長調 (ニちょうちょう) D major ニ短調 (ニたんちょう) D minor 変ニ長調 (へんニちょうちょう) D flat major And 7 more. Jinuma: Japanese Dictionary · Word lists