shimPronunciation: (shim), [key]
—n., v., shimmed, shim•ming.
a thin slip or wedge of metal, wood, etc., for driving into crevices, as between machine parts to compensate for wear, or beneath bedplates, large stones, etc., to level them.
to fill out or bring to a level by inserting a shim or shims.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.