The Collaborative International Dictionary of English v.0.48:

Unchild \Un*child"\, v. t. [1st pref. un- + child.]
   [1913 Webster]
   1. To bereave of children; to make childless. --Shak.
      [1913 Webster]

   2. To make unlike a child; to divest of the characteristics
      of a child. --Bp. Hall.
      [1913 Webster]