wedge

n. 1 piece of tapering wood or metal etc. Driven between two objects or parts to secure or separate them. 2 anything resembling a wedge. 3 golf club with a wedge-shaped head. v. (-ging) 1 secure or fasten with a wedge. 2 force open or apart with a wedge. 3 (foll. By in, into) pack or thrust (a thing or oneself) tightly in or into.  thin end of the wedge colloq. Thing of little importance in itself, but likely to lead to more serious developments. [old english]

n. 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.