verb (v)

• take temporary possession of as a security, by legal authority(verb.possession)

  Example:
  The customs agents impounded the illegal shipment.
  

  Synonym:
  attach, confiscate, seize, sequester
  

  source: wordnet30
• place or shut up in a pound(verb.contact)

  Synonym:
  pound
  

  source: wordnet30
• 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.(verb)

  source: webster1913