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Synonyms

rectilinear

American  
[rek-tl-in-ee-er] / ˌrɛk tlˈɪn i ər /
Or rectilineal

adjective

  1. forming a straight line.

  2. formed by straight lines.

  3. characterized by straight lines.

  4. moving in a straight line.


rectilinear British  
/ ˌrɛktɪˈlɪnɪə /

adjective

  1. in, moving in, or characterized by a straight line or lines

    the rectilinear propagation of light

  2. consisting of, bounded by, or formed by a straight line or lines

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

rectilinear Scientific  
/ rĕk′tə-lĭnē-ər /
  1. Relating to, consisting of, or moving in a straight line or lines.


Other Word Forms

Derived Forms

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.

Keep Reading on Vocabulary.com

Vocabulary lists containing rectilinear

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

Scholl explains that At Attin features a rectilinear grid plan city center, wrapped by suburbia in a more circular pattern that “is recognizable from space.”

From Los Angeles Times • Dec. 11, 2024

There is, however, one group of burrowing creatures that uses rectilinear locomotion.

From Slate • Mar. 8, 2024

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

We may translate this to mean that he started the process of carving a statue by trying to visualize a figure in the rough, rectilinear block as it came to him from the quarry.

From "History of Art, Volume 1" by H.W. Janson

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