n. Name for a person standing in a toilet cubicle and taking it so hard up the sphincter that the pleasure they endure causes them to bite down on the windowsill in front.

Often refers to homosexual males, much like pillow biter, it can also refer to any person where the server is going in dry.
"Dave is such a sill chewer, he minces around town in a boob tube"

"What are you looking at sill chewer!"
by Refreshment Boxx April 4, 2010
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