Tau'to-chrōne, n.

n. [Fr. tautochrone, from Gr. ταὐτό, for τὸ αὐτό, just the same, and χρόνος, time.] (Math.) A curve line, such that a heavy body, descending along it, by the action of gravity will always arrive at the lowest point in the same time, wherever in the curve it may begin to fall; an inverted cycloid with its base horizontal; a brachystochrone.