youthfulness 

英汉解释

n. 少壮

同义词

n. juvenility，youth

参考例句

1. Youthfulness is a matter of attitude to life , noe of the year of birth.
年轻是一种对生活的态度，而不是出生的年份。
2. But of course we're actually about extending or restoring physical and mental youthfulness and vitality.
但是，我们当然实际上是扩展和保持体力的和精神的年轻和活力。
3. White roses: unity, loyalty, reverence, humility, sincerity, purity, silence and innocence as well as youthfulness.
白色玫瑰，一体，忠诚，仁慈，衷心，纯洁，安静，天真和青春。

英英解释

n.
  1. the freshness and vitality characteristic of a young person

网络释义

youthfulness
青年; 或青年性; 富有青春活力; 年轻有活力;