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]