The Collaborative International Dictionary of English v.0.48:

Unappropriate \Un`ap*pro"pri*ate\, a. [Pref. un- not +
   appropriate, a.]
   1. Inappropriate; unsuitable.
      [1913 Webster]

   2. Not appropriated. --Bp. Warburton.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Unappropriate \Un`ap*pro"pri*ate\, v. t. [1st pref. un- +
   appropriate, v. t.]
   To take from private possession; to restore to the possession
   or right of all; as, to unappropriate a monopoly. [R.]
   --Milton.
   [1913 Webster]