二段活用
Meanings
1
nidan conjugation; bigrade conjugation
A classical Japanese verb conjugation class with two base vowels (e.g., 上二段 and 下二段). Used in historical grammar; modern equivalents are 上一段 and 下一段.
Nidan conjugation is one of the conjugations studied in classical grammar.
The bigrade conjugation is the origin of the modern monograde conjugation.