| Subject | English | Japanese |
| gen. | n Collections of the Twenty-One Eras | 二十一代集 |
| gen. | ctr counter for collections or assemblies of flat objects | 枚組み (e.g. CDs, DVDs, etc.) |
| gen. | ctr counter for collections or assemblies of flat objects | 枚組 (e.g. CDs, DVDs, etc.) |
| gen. | n the six ancient Japanese historical collections compiled between the Nara and Heian periods | 六国史 |
| gen. | n twenty-one collections of waka compiled by imperial command | 二十一代集 (early Heian to early Muromachi) |