Main Entry: di·rec·trix

Pronunciation: \-ˈrek-triks\

Function: noun

Inflected Form(s): plural di·rec·trix·es \-trik-səz\ also di·rec·tri·ces \-trə-ˌsēz\

Etymology: Medieval Latin, feminine of Late Latin director, from Latin dirigere

Date: 1622

1 archaic : directress
2 : a fixed curve with which a generatrix maintains a given relationship in generating a geometric figure; specifically : a straight line the distance to which from any point of a conic section is in fixed ratio to the distance from the same point to a focus