having no consciousness; inanimate; inert; senseless.

not capable of thinking rationally; irrational.

(phys.) the matter, tendency of which is to remain at rest if at rest or, if moving, to keep moving in the same direction, unless affected by some outside force; an inert object.

(phil.) the tendency to be ignorant; ignorance.

(psych.) the deepest, inaccessible level of the psyche in which are present, in dynamic state, repressed impulses and memories; the unconscious.