lettre de cachet*: Meaning and Definition of

let•tre de ca•chet

Pronunciation: (le-tr du ka-she'), [key]
— pl. let•tres de ca•chet
  1. a letter under the seal of the sovereign, esp. one ordering imprisonment, frequently without trial.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.