[1] : The Collaborative International Dictionary of English v.0.48

impassive \impas"sive\, a.
   not susceptible of pain or suffering; apathetic; impassible;
   unmoved.
   1913 webster

         impassive as the marble in the quarry.   --de quincey.
   1913 webster

         on the impassive ice the lightings play. --pope.
   -- impas"sively, adv. -- impas"siveness, n.
   1913 webster
see also:
impas"sively impas"siveness 

[2] : WordNet (r) 2.0

impassive
     adj 1: having or revealing little emotion or sensibility; not
            easily aroused or excited; "her impassive remoteness";
            "he remained impassive, showing neither interest in
            nor concern for our plight"- nordhoff  hall; "a
            silent stolid creature who took it all as a matter of
            course"-virginia woolf; "her face showed nothing but
            stolid indifference" syn: stolid
     2: deliberately impassive in manner; "deadpan humor"; "his face
        remained expressionless as the verdict was read" syn: deadpan,
         expressionless, poker-faced, unexpressive
see also:
stolid deadpan expressionless poker-faced unexpressive 

[3] : Moby Thesaurus II by Grady Ward, 1.0

183 moby thesaurus words for "impassive":
   olympian, affectless, aloof, anesthetized, apathetic, arctic,
   at rest, autistic, backward, bashful, blank, blunt, bored, bovine,
   callous, calm, careless, catatonic, chill, chilled, chilly,
   cloistered, cold, cold as charity, cold-blooded, coldhearted,
   collected, composed, constrained, contained, controlled, cool,
   deadpan, detached, discreet, disinterested, dispassionate, distant,
   drugged, dry, dull, dwindling, ebbing, emotionally dead,
   emotionless, empty, even-tempered, even-tenored, expressionless,
   fishy, forbidding, frigid, frosted, frosty, frozen, glassy,
   guarded, halcyon, hardened, heartless, heedless, hushed, icy,
   immovable, impassible, impersonal, imperturbable, inaccessible,
   incurious, indifferent, indurated, inexcitable, inexpressive,
   inirritable, insensible, insensitive, insentient, insouciant,
   insusceptible, introverted, isolated, lackadaisical, listless,
   matter-of-fact, mindless, modest, moldering, nonchalant,
   nonemotional, objective, obtuse, offish, out of touch, pacific,
   passionless, patient, peaceable, peaceful, phlegmatic, placid,
   poker-faced, quiescent, quiet, regardless, remote, removed,
   reposeful, reposing, repressed, reserved, restful, resting,
   restrained, reticent, retiring, secluded, self-absorbed,
   sequestered, sequestrated, serene, sheltered, shrinking, smooth,
   soulless, spiritless, standoff, standoffish, steady, still,
   still as death, stillish, stilly, stoic, stoical, stolid, stony,
   subdued, subsiding, suppressed, taciturn, tranquil, unaffable,
   unaffectionate, unagitated, unapproachable, uncaring, unconcerned,
   uncongenial, undemonstrative, undisturbable, undisturbed,
   unemotional, unexcitable, unexpansive, unexpressive, unfeeling,
   unflappable, ungenial, unimpassioned, unimpressible,
   unimpressionable, uninquiring, uninterested, uninvolved,
   unirritable, unloving, unmindful, unmoved, unnervous, unpassionate,
   unperturbed, unresponding, unresponsive, unruffled, unstirring,
   unsusceptible, unsympathetic, untouchable, untroubled, vacant,
   waning, withdrawn, wooden

Impassive >> I Words
Impassive, definition of term: Impassive
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