Source : Webster's Revised Unabridged Dictionary (1913)

Aventure \A*ven"ture\ (?; 135), n. [See {Adventure}, n.]
   1. Accident; chance; adventure. [Obs.] --Chaucer.

   2. (Old Law) A mischance causing a person's death without
      felony, as by drowning, or falling into the fire.