insensible

Concise Oxford English Dictionary © 2008 Oxford University Press:
insensible/ɪnˈsensəbl/

▶adjective

• 1 without one's mental faculties; unconscious.

  ■ numb; without feeling.

• 2 (insensible of/to) unaware of or indifferent to.

• 3 too small or gradual to be perceived.

– derivatives
insensibly adverb,
insensibility noun.