Tautochrone
Pronunciation : Tau"to*chrone
Part of Speech : n.
Etymology : [Gr. tautochrone.] (Math.)
Definition : Defn: 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.
Source : Webster's Unabridged Dictionary, 1913