That which impels or gives an impulse; an impelling agent.
One whose behaviour or personality is characterized by being impulsive.
Acting momentarily, or by impulse; not continuous – said of forces.
Having the power of driving or impelling; giving an impulse; moving; impellent.
Actuated by impulse or by transient feelings; inclined to make rapid decisions without due consideration.
Characterized by an absence of sleep.