Source : Webster's Revised Unabridged Dictionary (1913)

Spit \Spit\, v. i.
   1. To throw out saliva from the mouth.

   2. To rain or snow slightly, or with sprinkles.

            It had been spitting with rain.       --Dickens.

   {To spit on} or {upon}, to insult grossly; to treat with
      contempt. ``Spitting upon all antiquity.'' --South.