adjective

1. lacking sensation; not having the power to perceive with the senses
2. having lost sensation; unconscious
3. not recognizing or realizing; unaware; indifferent
4. not responsive emotionally; without feeling
5. so small, slight, or gradual as to be virtually imperceptible
6. not intelligible; without meaning: now chiefly in legal use
7. Obsolete senseless; stupid

Etymology: OFr < L insensibilis: see in- & sensible