一世一代 いっせいちだい Also written いっせいいちだい Meanings Noun, の-adjective once in a lifetime; the first and last occurrence (event, experience) of one's lifetime Kanji 一 one. Read as イチ. 世 generation. Read as セイ. 代 era. Read as ダイ. Word lists Yojijukugo (四字熟語) Jinuma: Japanese Dictionary · Word lists