Knifeedge
Pronunciation : Knife"*edge`
Part of Speech : n.
Definition : Defn: 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. Knife-edge file. See Illust. of File.
(Mech.)
Source : Webster's Unabridged Dictionary, 1913