impulsive

• characterized by undue haste and lack of thought or deliberation
• determined by chance or impulse or whim rather than by necessity or reason
• having the power of driving or impelling
• proceeding from natural feeling or impulse without external stimulus
• without forethought
• Actuated by impulse or by transient feelings
• Acting momentarily, or by impulse
• That which impels or gives an impulse

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