・be young in years 年が若い.

・be getting along [on] in years 年をとっていく.

・He is young [old] for his years. 年齢の割には若い[ふけている].

・Years bring wisdom. 《諺》 年をとると知恵がつく, 「亀の甲より年の功」.

3 (特定の計算法による)一年, 年度.

・an astral year＝sidereal year.

・an astronomical [a natural, solar] year＝tropical year.

・a calendar [civil, legal] year 暦年.

・a Christian [a Church, an ecclesiastical] year キリスト教暦年《Advent (降臨節)に始まる》.

・the Gregorian [Julian] year 新[旧]暦.

・the school year＝academic year.