rectilinear
Americanadjective
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forming a straight line.
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formed by straight lines.
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characterized by straight lines.
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moving in a straight line.
adjective
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in, moving in, or characterized by a straight line or lines
the rectilinear propagation of light
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consisting of, bounded by, or formed by a straight line or lines
Other Word Forms
- rectilinearly adverb
Etymology
Origin of rectilinear
1650–60; < Late Latin rēctilīne ( us ) ( rēcti- recti- + līne ( a ) line 1 + -us adj. suffix) + -ar 1
Explanation
In math, a rectilinear shape is made up of straight lines. A square and a rectangle are both rectilinear. Rectilinear is used to mean "straight," so if something moves in a straight line, it has rectilinear motion. A photographer's rectilinear lens reflects images accurately, so their straight lines don't appear curved. This word comes from the Latin root rectus, meaning "straight." In geometry, the meaning goes beyond that — a rectilinear polygon has straight sides that meet at a 90 degree angle. So from your geometry teacher's perspective, a rectangular speed limit sign is rectilinear but an octagonal stop sign is not.
Vocabulary lists containing rectilinear
Geometry - Introductory
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Geometry (Base List)
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Measurement and Data
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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.
Lowry’s rectilinear buildings suggest immobility beyond time, and urban orderliness without elegance.
From The Wall Street Journal • Oct. 31, 2025
Although rectilinear movement works well on flat ground, a burrowing movement “has to go all the way around the body” simply because the same friction exists on all sides of a creature.
From Slate • Mar. 8, 2024
The brightly lighted curve visually erased the sharp, angled edge that made any rectilinear painting into a figure standing against the wall’s ground.
From Los Angeles Times • Oct. 25, 2023
Inside Notre-Dame it is still a futuristic film décor - a towering mass of rectilinear metal scaffolding set against the curves and arches of the ancient Gothic stone.
From BBC • Apr. 14, 2023
And it may be noted that Oresme had grasped the crucial principle, that a combination of circular movements could produce the appearance of rectilinear movement, apparently independently of any Arabic source.
From "The Invention of Science" by David Wootton
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.
