The word "pivotal" has multiple meanings, but it generally refers to something that is crucial or essential in determining a final outcome. It can also refer to an event, moment, or point of rotation around which another object turns, much like how the word pivotal is used in mathematics when describing points on a curve where the curvature changes sharply. In essence, "pivotal" implies something that plays a significant role in turning things around or making a difference in an important situation.