Unthinking \Un*think"ing\, a. 1. Not thinking; not heedful; thoughtless; inconsiderate; as, unthinking youth. [1913 Webster] 2. Not indicating thought or reflection; thoughtless. [1913 Webster] With earnest eyes, and round unthinking face, He first the snuffbox opened, then the case. --Pope. [1913 Webster] -- {Un*think"ing*ly}, adv. -- {Un*think"ing*ness}, n. [1913 Webster]