| Word form | keitei |
| Original script | 兄弟 |
| LWT meaning(s) | |
| Word meaning | formal term |
| Comments on word | same origin and spelling as kyōdai |
| Analyzability | analyzable derived |
| Gloss | kei-tei older_brother-younger_brother |
| Age | Early Modern Japanese [21] (1604–1867) |
| Lexical stratum | kango (kan’on) |
| Year | 日葡辞書 (1603) |
| Register | Formal |