The Collaborative International Dictionary of English v.0.48:

Sweven \Swe"ven\, n. [AS. swefen sleep, dream; akin to swebban,
   swefian, to put to sleep, to kill. [root]176. See
   Somnolent.]
   A vision seen in sleep; a dream. [Obs.] --Wycliff (Acts ii.
   17).
   [1913 Webster]

         I defy both sweven and dream.            --Chaucer.
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