1.Definition: characterized by undue haste and lack of thought or deliberation
"Liable to such impulsive acts as hugging strangers"
2.Definition: determined by chance or impulse or whim rather than by necessity or reason
3.Definition: having the power of driving or impelling
"An impulsive force"
4.Definition: proceeding from natural feeling or impulse without external stimulus
"An impulsive gesture of affection"
5.Definition: without forethought
"Letting him borrow her car was an impulsive act that she immediately regretted"