The meaning of Tautochrone and additional information.

Tautochrone(n.) A curved 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; as, an inverted cycloid with its base horizontal is a tautochrone.

Tautochronous(a.) Occupying the same time; pertaining to, or having the properties of, a tautochrone.