पुरुषः man, परेतकाले at the time of death, यत् whatever, कर्म actions, प्रतिपद्यते does, अधर्म्यम् unrighteous, तत् such, कर्म action, आत्मनः yourself, विनाशाय for destruction, प्रतिपन्नः undertaken, असि you are.

You have resorted to unrighteous action like a dying man. This will spell your destruction.