nBrachystochrone(Math) A curve, in which a body, starting from a given point, and descending solely by the force of gravity, will reach another given point in a shorter time than it could by any other path. This curve of quickest descent, as it is sometimes called, is, in a vacuum, the same as the cycloid.
Century Dictionary and Cyclopedia
nbrachystochroneErroneous, though the original and until recently the usual, spelling of brachistochrone.
Webster's Revised Unabridged Dictionary
Incorrect for brachistochrone, fr. Gr. bra`chistos shortest (superl. of brachy`s short) + time : cf. F. brachistochrone,.