di·​rec·​trix də-ˈrek-triks How to pronounce directrix (audio)
plural directrixes də-ˈrek-trik-səz How to pronounce directrix (audio) also directrices də-ˈrek-trə-ˌsēz How to pronounce directrix (audio)
archaic : directress
: 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

Word History


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

First Known Use

1622, in the meaning defined at sense 1

Time Traveler
The first known use of directrix was in 1622

Dictionary Entries Near directrix

Cite this Entry

“Directrix.” Dictionary, Merriam-Webster, Accessed 21 Jun. 2024.

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