Source : Webster's Revised Unabridged Dictionary (1913)

Supersedeas \Su`per*se"de*as\, n. [L., suspend, set aside, stay,
   2d pers. sing. present subjunctive of supersedere. See
   {Supersede}.] (Law)
   A writ of command to suspend the powers of an officer in
   certain cases, or to stay proceedings under another writ.
   --Blackstone.