Source : Webster's Revised Unabridged Dictionary (1913)

Impound \Im*pound"\, v. t. [imp. & p. p. {Impounded}; p. pr. &
   vb. n. {Impounding}.]
   To shut up or place in an inclosure called a pound; hence, to
   hold in the custody of a court; as, to impound stray cattle;
   to impound a document for safe keeping.

         But taken and impounded as a stray, The king of Scots.
                                                  --Shak.

Source : WordNet®

impounding
     n : placing private property in the custody of an officer of the
         law [syn: {impoundment}, {internment}, {poundage}]