Insensible, a.
Etymology: [L. insensibilis: cf. F. insensible. See In- not, and Sensible.]
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.
1 more senses
Syn. -- Imperceptible; imperceivable; dull; stupid; torpid; numb; unfeeling; apathetic; stoical; impassive; indifferent; unsusceptible; hard; callous.
Shades of meaning
Fernald has no entry of its own for insensible; he lists it under brutish.
He lists it without comment; the entries above explain its neighbors.