老成る ませる to be precocious Meanings ichidan verb, intransitive, usually in kana to be precocious; to be mature for one's age; to seem grown-up; to seem mature Its kanji 老 ロウ · お.いる、ふ.ける old man, old age, grow old 成 セイ、ジョウ · な.る、な.す、-な.す turn into, become, get, grow, elapse, reach