ADJECTIVE (2)

1. not responsive to physical stimuli;
- Example: "insensitive to radiation"

2. deficient in human sensibility; not mentally or morally sensitive;
- Example: "insensitive to the needs of the patients"

The Collaborative International Dictionary of English v.0.48:

Insensitive \In*sen"si*tive\, a.
   Not sensitive; wanting sensation, or wanting acute
   sensibility. --Tillotson. --Ruskin.
   [1913 Webster]

WordNet (r) 3.0 (2006):

insensitive
    adj 1: not responsive to physical stimuli; "insensitive to
           radiation" [ant: sensitive]
    2: deficient in human sensibility; not mentally or morally
       sensitive; "insensitive to the needs of the patients" [ant:
       sensitive]

Moby Thesaurus II by Grady Ward, 1.0:

103 Moby Thesaurus words for "insensitive":
   Philistine, aloof, anesthetic, anesthetized, asleep, benumbed,
   blanket, bloodless, boorish, caddish, callous, calloused,
   case-hardened, casual, coarse, cold, cold of heart, coldblooded,
   coldhearted, crude, dead, deadened, dull, flinthearted, flinty,
   general, hard, hard of heart, hardened, hardhearted, heartless,
   ill-bred, impassible, impassive, imperceptive, impercipient,
   impervious, imprudent, inconsiderate, incurious, indifferent,
   indiscreet, indiscriminate, indiscriminative, indurated, insensate,
   insensible, insentient, inured, loutish, louty, nasty,
   nonjudgmental, numb, numbed, obdurate, obtuse, offensive,
   pachydermatous, promiscuous, proof against, rocky, senseless,
   steeled against, steely, stony, stonyhearted, tactless,
   thick-skinned, thick-witted, unconcerned, uncritical,
   uncriticizing, undemanding, undifferentiating, undiscreet,
   undiscriminating, undiscriminative, unexacting, unfastidious,
   unfeeling, unfelt, unfeminine, ungenteel, ungentle, ungentlemanly,
   unimpressible, unimpressionable, unladylike, unmerciful,
   unmeticulous, unnatural, unparticular, unperceptive, unrefined,
   unresponsive, unselective, unsolicitous, unsubtle, unsusceptible,
   untactful, vulgar, wholesale