Source : Webster's Revised Unabridged Dictionary (1913)

Interior \In*te"ri*or\, a. [L., compar. fr. inter between: cf.
   F. int['e]rieur. See {Inter-}, and cf. {Intimate}.]
   1. Being within any limits, inclosure, or substance; inside;
      internal; inner; -- opposed to {exterior}, or
      {superficial}; as, the interior apartments of a house; the
      interior surface of a hollow ball.

   2. Remote from the limits, frontier, or shore; inland; as,
      the interior parts of a region or country.

   {Interior angle} (Geom.), an angle formed between two sides,
      within any rectilinear figure, as a polygon, or between
      two parallel lines by these lines and another intersecting
      them; -- called also {internal angle}.

   {Interior planets} (Astron.), those planets within the orbit
      of the earth.

   {Interior screw}, a screw cut on an interior surface, as in a
      nut; a female screw.

   Syn: Internal; inside; inner; inland; inward.

Interior \In*te"ri*or\, n.
   1. That which is within; the internal or inner part of a
      thing; the inside.

   2. The inland part of a country, state, or kingdom.

   {Department of the Interior}, that department of the
      government of the United States which has charge of
      pensions, patents, public lands and surveys, the Indians,
      education, etc.; that department of the government of a
      country which is specially charged with the internal
      affairs of that country; the home department.

   {Secretary of the Interior}, the cabinet officer who, in the
      United States, is at the head of the Department of the
      Interior.

Source : WordNet®

interior
     adj 1: situated within or suitable for inside a building; "an
            interior scene"; "interior decoration"; "an interior
            bathroom without windows" [ant: {exterior}]
     2: inside the country; "the British Home Office has broader
        responsibilities than the United States Department of the
        Interior"; "the nation's internal politics" [syn: {home(a)},
         {interior(a)}, {internal}, {national}]
     3: located inward; "Beethoven's manuscript looks like a bloody
        record of a tremendous inner battle"- Leonard Bernstein;
        "she thinks she has no soul, no interior life, but the
        truth is that she has no access to it"- David Denby; "an
        internal sense of rightousness"- A.R.Gurney,Jr. [syn: {inner},
         {internal}]
     4: inside and toward a center; "interior regions of the earth"
     5: of or coming from the middle of a region or country;
        "upcountry districts" [syn: {midland}, {upcountry}]

interior
     n 1: the region that is inside of something [syn: {inside}] [ant:
           {outside}]
     2: the inner or enclosed surface of something [syn: {inside}]
        [ant: {outside}]
     3: the United States federal department charged with
        conservation and the development of natural resources;
        created in 1849 [syn: {Department of the Interior}, {Interior
        Department}, {DoI}]