Source : Webster's Revised Unabridged Dictionary (1913)

Civilian \Ci*vil"ian\, n. [From {Civil}]
   1. One skilled in the civil law.

            Ancient civilians and writers upon government.
                                                  --Swift.

   2. A student of the civil law at a university or college.
      --R. Graves.

   3. One whose pursuits are those of civil life, not military
      or clerical.

Source : WordNet®

civilian
     adj : associated with or performed by civilians as contrasted with
           the military; "civilian clothing"; "civilian life"
           [ant: {military}]

civilian
     n : a nonmilitary citizen [ant: {serviceman}]