What is the meaning of Wedge?

A piece of metal, or other hard material, thick at one end, and tapering to a thin edge at the other, used in splitting wood, rocks, etc., in raising heavy bodies, and the like. It is one of the six elementary machines called the mechanical powers. See Illust. of Mechanical powers, under Mechanical.

Source: Webster’s Revised Unabridged Dictionary (1913), via OPTED