The extreme movement given to a sliding or vibrating
   reciprocating piece by a cam, crank, eccentric, or the like; travel;
   stroke; as, the throw of a slide valve. Also, frequently, the length of
   the radius of a crank, or the eccentricity of an eccentric; as, the
   throw of the crank of a steam engine is equal to half the stroke of the
   piston.