impulsive

adj

1. Having the power of driving or impelling; giving an impulse; moving; impellent.

   “Poor men! poor papers! We and they / Do some impulsive force obey.”

2. Actuated by impulse or by transient feelings; inclined to make rapid decisions without due consideration.

   “my heart, impulsive and wayward”

   “Americans are not libertarians in the Cato Institute sense of the word, but they are folk libertarians in this sense of impulsive behaviour, which is a feature of American life that anyone who wants to govern the United States, Democratic or Republican, has to be aware of.”

3. Acting momentarily, or by impulse; not continuous – said of forces.

noun

1. That which impels or gives an impulse; an impelling agent.

   “Notwithstanding all which Motives and impulsives , Sir Thomas Overbury refused to be sent abroad , with such terms”

2. One whose behaviour or personality is characterized by being impulsive.