Insensible

Part of speech: adjective (a.)

1. Destitute of the power of feeling or perceiving; wanting bodily sensibility. Milton.

2. Not susceptible of emotion or passion; void of feeling; apathetic; unconcerned; indifferent; as, insensible to danger, fear, love, etc.; -- often used with of or to. Accept an obligation without being a slave to the giver, or insensible to his kindness. Sir H. Wotton. Lost in their loves, insensible of shame. Dryden.

3. Incapable of being perceived by the senses; imperceptible. Hence: Progressing by imperceptible degrees; slow; gradual; as, insensible motion. Two small and almost insensible pricks were found upon Cleopatra's arm. Sir T. Browne. They fall away, And languish with insensible decay. Dryden.

4. Not sensible or reasonable; meaningless. [Obs.] If it make the indictment be insensible or uncertain, it shall be quashed. Sir M. Hale.

Synonyms: Imperceptible; imperceivable; dull; stupid; torpid; numb; unfeeling; apathetic; stoical; impassive; indifferent; unsusceptible; hard; callous.