precocious

形容词 precocious:

1. characterized by or characteristic of exceptionally early development or maturity (especially in mental aptitude)
2. appearing or developing early

1. Childhood hardships matured in him a precocious sense of responsibility.
   童年的艰苦生活使他提早形成了一种过早具有的责任感。
2. That child is far too precocious.
   孩子过于老成。
3. His son is a precocious child who could play the piano at the age of three.
   他的儿子是一个三岁就能弹奏钢琴的早慧儿童。

pre.co.cious

adj.（形容词）
Manifesting or characterized by unusually early development or maturity, especially in mental aptitude.
早熟的：表明或以不寻常的过早发展或成熟为特点的，尤指智力
Botany Blossoming before the appearance of leaves.
【植物学】 早开的：叶子出现之前开花的

来源：
From Latin praecox praecoc- [premature]
源自 拉丁语 praecox praecoc- [早熟的]
from praecoquere [to boil before, ripen fully]
源自 praecoquere [先于…沸腾的，熟透的]
prae- [pre-]
prae- [前缀，表.先于.]
coquere [to cook, ripen] * see pek w-
coquere [烧，成熟] *参见 pek w-

【引伸】
preco.ciously
adv.（副词）
precoc.ity