adj.年輕的；有青春活力的；年輕人的；(地質(zhì)學(xué))幼年期的

No one can remain youthful forever. 沒有人能永保青春。

His youthful escapades came back to haunt him. 年輕時(shí)的胡作非為時(shí)常令他感到苦惱。

He was youthful but white-haired. 他雖已白發(fā)蒼蒼,卻仍然朝氣蓬勃。

If you want to retain youthful vigor,you have to take regular exercise. 如果你想保持青春活力，你就得經(jīng)常鍛煉。

He was full of youthful idealism. 他滿腦子都是年輕人的理想主義。

n.年輕