shim(n = noun.artifact) - a thin wedge of material (wood or metal or stone) for driving into crevices;
is a kind of wedge

1.  A kind of shallow plow used in tillage to break the ground, and clear it of weeds. [1913 Webster]

2.  A thin piece of metal placed between two parts to make a fit. [1913 Webster]

shim, n. & v.
--n. a thin strip of material used in machinery etc. to make parts fit.
--v.tr. (shimmed, shimming) fit or fill up with a shim.

Etymology:
18th c.: orig. unkn.