Source : Webster's Revised Unabridged Dictionary (1913)

Tossing \Toss"ing\, n.
   1. The act of throwing upward; a rising and falling suddenly;
      a rolling and tumbling.

   2. (Mining)
      (a) A process which consists in washing ores by violent
          agitation in water, in order to separate the lighter
          or earhy particles; -- called also {tozing}, and
          {treloobing}, in Cornwall. --Pryce.
      (b) A process for refining tin by dropping it through the
          air while melted.