成せい年ねん者しゃ

Meanings

1

adult; person of full age

Formal or legal term for a person who has reached the age of majority. In everyday speech, 大人 (おとな) is more common.

日本にほんでは、成せい年ねん者しゃは20歳はたち以い上じょうと定てい義ぎされていた。
In Japan, an adult was defined as a person aged 20 or older.
成せい年ねん者しゃとしての権けん利りと責せき任にんを理り解かいする必ひつ要ようがある。
It is necessary to understand the rights and responsibilities as an adult.