Merriam-Webster Collegiate Dictionary - pivot

 I. noun  Etymology: French  Date: 1611  1. a shaft or pin on which something turns  2.  a. a person, thing, or factor having a major or central role, function, or effect  b. a key player or position; specifically an offensive position of a basketball player standing usually with back to the basket to relay passes, shoot, or provide a screen for teammates  3. the action of ~ing; especially the action in basketball of stepping with one foot while keeping the other foot at its point of contact with the floor  II. adjective  Date: 1796  1. turning on or as if on a ~  2. ~al  III. verb  Date: 1841  intransitive verb to turn on or as if on a ~  transitive verb  1. to provide with, mount on, or attach by a ~  2. to cause to ~  • ~able adjective