Source : Webster's Revised Unabridged Dictionary (1913)

Separatrix \Sep`a*ra"trix\, n.; pl. L. {-trices}, E. {-trixes}.
   [L., she that separates.] (Arith.)
   The decimal point; the dot placed at the left of a decimal
   fraction, to separate it from the whole number which it
   follows. The term is sometimes also applied to other marks of
   separation.

Quadratrix \Quad*ra"trix\, n.; pl. {-trixes}, or {-trices}.
   [NL.] (Geom.)
   A curve made use of in the quadrature of other curves; as the
   quadratrix, of Dinostratus, or of Tschirnhausen.

Impropriatrix \Im*pro`pri*a"trix\, n.; pl. E. {-trixes}, L.
   {-trices}.
   A female impropriator.