ful·crum 
(flkrəm, fŭl-)
(flkrəm, fŭl-)n. pl. ful·crums or ful·cra (-krə)
1. The point or support on which a lever pivots.
2. Zoology An anatomical structure that acts as a hinge or a point of support.
3. An agent through which vital powers are exercised.
[Latin, bedpost, from fulcīre, to support.]
fulcrumrelative position of the fulcrum in three basic types of levers, with arrows indicating the direction of the effort and the downward force of the load