Not perceptible by the senses; imperceptible; inappreciable.
Not sensible to the mind; not consciously apprehended or appreciated; unconscious.
Without the power of feeling or sensation; without corporeal sensibility.
Not susceptible of emotion or passion; void of feeling or tenderness: as, to be insensible to the sufferings of others.
Void of sense or meaning; meaningless.
Dull, torpid, senseless, unconscious, unfeeling, unsusceptible, indifferent, hard, callous.
noun.
One who is lacking in sensibility; a thoroughly apathetic person.