PIVOT

I. noun Etymology: French Date: 1611 a shaft or pin on which something turns, 2. a person, thing, or factor having a major or central role, function, or effect, a key player or position, the action of ~ing, II. adjective Date: 1796 turning on or as if on a ~, ~al , III. verb Date: 1841 intransitive verb to turn on or as if on a ~, transitive verb to provide with, mount on, or attach by a ~, to cause to ~, ~able adjective