The term 'OUTER' can be used to describe a variety of concepts, including the OUTMOST, SURFACE, OUTWARD, OUTSIDE, EXTRINSIC, OVER, exo, EXTRANEOUS, EXTERIOR, EXTERNAL, ectal, and SPACE. The OUTMOST refers to the furthest point or boundary from the center, while the SURFACE is the outermost layer of an object. OUTWARD is the direction away from the center, and OUTSIDE is the area that lies beyond the boundaries of an object. EXTRINSIC is something that is not part of the essential nature of a thing, while OVER is the opposite of under. Exo is a prefix meaning OUTSIDE, and EXTRANEOUS means not essential or pertinent. EXTERIOR is the outer SURFACE or OUTSIDE of an object, and EXTERNAL is something that is on the OUTSIDE or beyond the limits of a thing. Ectal is something that is situated on the OUTSIDE, and SPACE is an area that is free or available for occupancy.