一世いっせい

1. 1generation ; lifetime Translated by Jiyomi
2. 2the age ; the day Translated by Jiyomi
3. 3the first (e.g. Elizabeth I) Translated by Jiyomi
4. 4issei ; first-generation Japanese (or Korean, etc.) Translated by Jiyomi

JMdict entry 1576180 · frequency rank 16. Source and licence.