a.

1. 衝動的；易衝動的；由衝動造成的
   He later regretted his impulsive decision.

   後來他懊悔憑衝動作出的決定。

   She is an impulsive person; we never know what she will do next.

   她是個容易衝動的人；我們從來不知道她下一步想做什麼。

2. 推進的，有推動力的
   an impulsive force

   推動力

3. 【物】衝力的

adj.

1. acting or done without forethought.
2. Physics  acting as an impulse.