directrix
Americannoun
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Geometry. a fixed line used in the description of a curve or surface.
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Archaic. a directress.
noun
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geometry a fixed reference line, situated on the convex side of a conic section, that is used when defining or calculating its eccentricity
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a directress
Gender
See -trix.
Etymology
Origin of directrix
From New Latin, dating back to 1615–25; see origin at direct, -trix
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Hyperbola with and directrix units to the right of the pole.
From Textbooks • Dec. 21, 2021
Hyperbola with and directrix units to the right of the pole.
From Textbooks • Dec. 21, 2021
Parabola with and directrix units to the right of the pole.
From Textbooks • Dec. 21, 2021
Ellipse with and directrix units to the right of the pole.
From Textbooks • Sep. 23, 2020
It declared that the central span of the contemplated bridge must be no less than 500 feet long, nor its elevation above the city directrix less than fifty feet.
From James B. Eads by How, Louis
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
