A rigid piece which is capable of turning about one point,
   or axis (the fulcrum), and in which are two or more other points where
   forces are applied; -- used for transmitting and modifying force and
   motion. Specif., a bar of metal, wood, or other rigid substance, used
   to exert a pressure, or sustain a weight, at one point of its length,
   by receiving a force or power at a second, and turning at a third on a
   fixed point called a fulcrum. It is usually named as the first of the
   six mechanical powers, and is of three kinds, according as either the
   fulcrum F, the weight W, or the power P, respectively, is situated
   between the other two, as in the figures.