Definition of "knife-edge" in English

noun

1. A piece of steel sharpened to an acute edge or angle, and resting on a smooth surface, serving as the axis of motion of a pendulum, scale beam, or other piece required to oscillate with the least possible friction.

2. (figuratively) A precarious balance that could be upset by a very small force in either direction.

   • The game was on a knife-edge.

3. Used other than figuratively or idiomatically: the edge of a knife.