Word Study
osculatrix
CIDE DICTIONARY
osculatrix, n. [NL.].
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. [1913 Webster]
For further exploring for "osculatrix" in Webster Dictionary Online