The Collaborative International Dictionary of English v.0.48:

Duress \Du"ress\, n. [OF. duresse, du?, hardship, severity, L.
   duritia, durities, fr. durus hard. See Dure.]
   1. Hardship; constraint; pressure; imprisonment; restraint of
      liberty.
      [1913 Webster]

            The agreements . . . made with the landlords during
            the time of slavery, are only the effect of duress
            and force.                            --Burke.
      [1913 Webster]

   2. (Law) The state of compulsion or necessity in which a
      person is influenced, whether by the unlawful restrain of
      his liberty or by actual or threatened physical violence,
      to incur a civil liability or to commit an offense.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Duress \Du*ress"\, v. t.
   To subject to duress. "The party duressed." --Bacon.
   [1913 Webster]

WordNet (r) 3.0 (2006):

duress
    n 1: compulsory force or threat; "confessed under duress"