The Collaborative International Dictionary of English v.0.48:

Sond \Sond\, Sonde \Sonde\, n. [AS. sand. See Send, v. t.]
   1. That which is sent; a message or messenger; hence, also, a
      visitation of providence; an affliction or trial. [Obs.]
      [1913 Webster]

            Ye have enough, parde, of Goddes sond. --Chaucer.
      [1913 Webster]

   2. (Rocketry) a rocket or balloon sent into the upper
      atmosphere to measure atmospheric conditions or other
      phenomena at altitudes unattainable by aircraft.
      [PJC]