osculatrix

Os`cu*la"trix, n.; pl. Osculatrixes. Etym: [NL.] (Geom.) Defn: A curve whose contact with a given curve, at a given point, is of a higher order (or involves the equality of a greater number of successive differential coefficients of the ordinates of the curves taken at that point) than that of any other curve of the same kind.

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