| 基語 | [きご, kigo] (n) parent language; root word [Add to Longdo] |
| 印欧基語 | [いんおうきご, in'oukigo] (n, adj-no) (See 印欧祖語) Proto-Indo-European (hypothetical language from which all Indo-European languages are derived) [Add to Longdo] |
| 共通基語 | [きょうつうきご, kyoutsuukigo] (n) protolanguage [Add to Longdo] |