Examples from the Web for spitball
Then take a wrapped straw, unwrap it, tear off a little piece of paper and make a spitball.
I thought I could go through the motion of throwing a spitball without letting it go.The Iron Puddler|James J. Davis
But the very first "spitball" which spattered upon the blackboard proved a disastrous missile for its thrower.Cy Whittaker's Place|Joseph C. Lincoln
There are also other modifications called "the fade away," "the spitball," and others.Outdoor Sports and Games|Claude H. Miller
He had never cared for the spitball, as he knew that sooner or later it destroyed a pitchers effectiveness.
Hooper was a spitball artist, and his moist slants kept the Giants guessing in the early part of the game.