Word Study
tautochrone
CIDE DICTIONARY
tautochrone, n. [Gr. , for the same + time: cf. F. tautochrone.].
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. [1913 Webster]
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