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plane

1
[ pleyn ]
/ pleɪn /
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See synonyms for: plane / planed / planing on Thesaurus.com
noun
adjective
flat or level, as a surface.
of or relating to planes or plane figures.
verb (used without object), planed, plan·ing.
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Origin of plane

1
First recorded in 1400–50 (for def. 9) (in the sense “to soar”); 1640–50 for noun and adjective senses; (noun) from Latin plānum “flat surface” (noun use of plānus “flat”); (adjective) from Latin plānus; first used to distinguish the geometrical senses formerly belonging to plain1; (in def. 5), shortened form of airplane, aeroplane, or hydroplane; (verb) late Middle English planen “(of a bird) to soar” (compare Middle French planer ); akin to plain1

OTHER WORDS FROM plane

planeness, noun

WORDS THAT MAY BE CONFUSED WITH plane

plain, plan, plane

Words nearby plane

Planck constant, Planck, Max, Planck's constant, Planck's law, Planck's radiation law, plane, plane angle, plane chart, plane geometry, plane iron, planeload

Other definitions for plane (2 of 3)

plane2
[ pleyn ]
/ pleɪn /
noun
Carpentry. any of various woodworking instruments for paring, truing, or smoothing, or for forming moldings, chamfers, rabbets, grooves, etc., by means of an inclined, adjustable blade moved along and against the piece being worked.
a trowellike tool for smoothing the surface of clay in a brick mold.
verb (used with object), planed, plan·ing.
to smooth or dress with or as if with a plane or a planer.
to remove by or as if by means of a plane (usually followed by away or off).
verb (used without object), planed, plan·ing.
to work with a plane.
to function as a plane.

Origin of plane

2
First recorded in 1375–1425; Middle English noun plane, plaine, pleine, from Middle French plan(n)e, Old French plaine, plane or directly from Late Latin plāna “plane, adze,” derivative of plānāre “to smooth,” itself derivative of Latin plānus plain1; Middle English verb plane(n), plaine, pleine, from Middle French planer or directly from Late Latin plānāre

Other definitions for plane (3 of 3)

plane3
[ pleyn ]
/ pleɪn /
noun
plane tree.

Origin of plane

3
First recorded in 1350–1400; Middle English plane, plaine, from Middle French plane, Old French pleine, plane, from Latin platanus, from Greek plátanos, derivative of platýs “wide, broad, flat” (with reference to the leaves)
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

MORE ABOUT PLANE

What does plane mean?

In geometry, a plane  is a flat, two-dimensional surface with an infinite height and width. It’s one of the basic concepts of geometry.

Think of a flat sheet of paper. A physical sheet of paper has three dimensions: length, width, and (a small) height. If that sheet of paper had zero height and its length and width extended forever, it would be a plane. Obviously, such a shape is theoretical—it’s used as a basis for geometric calculations.

A plane is one of several basic concepts students need to begin to understand geometry. Another is a point. Unlike a plane, it has no dimensions, such as length or width. It is found by using coordinates. A third concept is a line. Like a plane, a line also extends forever but only in two directions.

Understanding what a plane is matters because angles and two-dimensional shapes, such as squares, triangles, and circles, are represented as points, lines, and line segments on a plane. It also helps you understand three-dimensional space and three-dimensional objects, which have height as well as length and width. Plane has several other meanings, some of which have different roots. More generally, it can refer to any flat or level surface.

Why is plane important?

The first records of the word plane in a mathematical sense come from the early 1600s. It comes from the Latin plānum, meaning “flat surface,” which is a noun formed from the Latin adjective plānus, meaning “flat.”

Planes and many other basics of geometry are often credited to the Greek mathematician Euclid, who lived around the year 300 B.C. Euclid developed the idea of a plane, along with other fundamental concepts of geometry, such as points, lines, and two-dimensional shapes. All two-dimensional geometry exists on a plane. Because of this, geometry that deals with two-dimensional shapes is called plane geometry.

The other major type of geometry is solid geometry, which involves three-dimensional space and shapes, such as cubes and cylinders.

Did you know ... ?

Euclid’s conception of geometry, known as Euclidean geometry, provided almost the entire foundation of geometry for over 2,000 years until mathematicians explored non-Euclidean geometry in the 1800s.

What are real-life examples of plane?

We encounter planes all the time in everyday life, even though we might not use geometric terms to describe them.

 

 

What other words are related to plane?

Quiz yourself!

In geometry, a plane is a two-dimensional surface with:

A. infinite width and height.
B. infinite width and length.
C. infinite length and height.
D. infinite width, length, and height.

Words related to plane

airplane, craft, jet, ship, even, flat, flush, plain, regular, smooth, uniform, condition, degree, extension, face, facet, footing, grade, horizontal, obverse

How to use plane in a sentence

British Dictionary definitions for plane (1 of 3)

plane1
/ (pleɪn) /
noun
adjective
level or flat
maths (of a curve, figure, etc) lying entirely in one plane
verb (intr)

Derived forms of plane

planeness, noun

Word Origin for plane

C17: from Latin plānum level surface

British Dictionary definitions for plane (2 of 3)

plane2
/ (pleɪn) /
noun
a tool with an adjustable sharpened steel blade set obliquely in a wooden or iron body, for levelling or smoothing timber surfaces, cutting mouldings or grooves, etc
a flat tool, usually metal, for smoothing the surface of clay or plaster in a mould
verb (tr)
to level, smooth, or cut (timber, wooden articles, etc) using a plane or similar tool
(often foll by off) to remove using a plane

Word Origin for plane

C14: via Old French from Late Latin plāna plane, from plānāre to level

British Dictionary definitions for plane (3 of 3)

plane3
/ (pleɪn) /
noun
See plane tree
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

Scientific definitions for plane

plane
[ plān ]
Noun
A two-dimensional surface, any two of whose points can be joined by a straight line that lies entirely in the surface.
Adjective
Lying in a plane:a plane curve.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Cultural definitions for plane

plane

A geometrical location having only two dimensions — length and width (no height). (See coordinates and plane geometry.)

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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