What is the meaning of insensible?

adjective

• Incapable of physical sensation.
  • usage: "insensible to pain"; "insensible earth"
• Unaware of or indifferent to.
  • usage: "insensible to the suffering around him"
  • synonyms: unaffected
• Barely able to be perceived.
  • usage: "the transition was almost indiscernible"; "an almost insensible change"
  • synonyms: indiscernible, undetectable
• Unresponsive to stimulation.
  • usage: "he lay insensible where he had fallen"; "drugged and senseless"
  • synonyms: senseless