American Heritage Dictionary
(2)
Century Dictionary
(1)
GNU Webster's 1913
WordNet
(2)
Elsewhere on the web
Ewing was just perfecting his spitball, which would carry him through several good seasons.— Cincinnati Reds Blog
And then the obligatory spitball, courtesy one Coalition to Save Potrero: "What they're doing is more of a cookie-cutter design."— Curbed SF
Again, this is all a spitball (I am going to ask a gay person I know tomarrow about this).— Conservapedia - Recent changes [en]
His signature pitch was the spitball, so much so that Shocker was among the 17 major league pitchers allowed to continue using the pitch in the grandfather clause included in the spitball's prohibition.— The Hardball Times

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