Abutment \A*but"ment\ ([.a]*b[u^]t"ment), n.

1. State of abutting.

2. That on or against which a body abuts or presses; as
   (a) (Arch.) The solid part of a pier or wall, etc., which receives the thrust or lateral pressure of an arch, vault, or strut. --Gwilt.
   (b) (Mech.) A fixed point or surface from which resistance or reaction is obtained, as the cylinder head of a steam engine, the fulcrum of a lever, etc.
   (c) In breech-loading firearms, the block behind the barrel which receives the pressure due to recoil.

Source: Webster's Revised Unabridged Dictionary (1913)