Unconscious Un*con"scious, a. 1. Not conscious; having no consciousness or power of mental perception; without cerebral appreciation; hence, not knowing or regarding; ignorant; as, an unconscious man. --Cowper. 2. Not known or apprehended by consciousness; as, an unconscious cerebration. ``Unconscious causes.'' --Blackmore. 3. Having no knowledge by experience; -- followed by of; as, a mule unconscious of the yoke. --Pope. -- Un*con"scious-ly, adv. -- Un*con"scious*ness, n.