The Collaborative International Dictionary of English v.0.48:

Outside \Out"side`\, a.
   1. Of or pertaining to the outside; external; exterior;
      superficial.
      [1913 Webster]

   2. Reaching the extreme or farthest limit, as to extent,
      quantity, etc.; as, an outside estimate. [Colloq.]
      [1913 Webster]

   Outside finish (Arch.), a term for the minor parts, as
      corner boards, hanging stiles, etc., required to complete
      the exterior of a wooden building; -- rare in masonry.
      [1913 Webster]