未成 みせい Meanings Noun uncompleted; unfinished; crude Kanji 未 not yet. Read as ミ. 成 become. Read as セイ. Words containing 未成 未成年 (みせいねん) minority (i.e. being under age) 未成年者 (みせいねんしゃ) minor 未成線 (みせいせん) uncompleted (railway) line And 6 more. Jinuma: Japanese Dictionary · Word lists