'Impassive' definitions:

Definition of 'impassive'

(from WordNet)
adjective
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: impassive, stolid]
adjective
Deliberately impassive in manner; "deadpan humor"; "his face remained expressionless as the verdict was read" [syn: deadpan, expressionless, impassive, poker-faced, unexpressive]

Definition of 'Impassive'

From: GCIDE
  • Impassive \Im*pas"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. -- {Im*pas"sive*ly}, adv. -- {Im*pas"sive*ness}, n. [1913 Webster]

Synonyms of 'impassive'

From: Moby Thesaurus