a.

1. 精力旺盛的；精神飽滿的
   He is an energetic tennis player.

   他是個精力充沛的網球手。

2. 有力的；積極的
   an energetic campaigner in the cause of women's lib

   一位婦女解放事業的大力倡導者

adj.

1. showing or involving great energy or activity.
2. Physics  relating to energy.