plane
1 Americannoun
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a flat or level surface.
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Geometry. a surface generated by a straight line moving at a constant velocity with respect to a fixed point.
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Fine Arts. an area of a two-dimensional surface having determinate extension and spatial direction or position.
oblique plane; horizontal plane.
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a level of dignity, character, existence, development, or the like.
a high moral plane.
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Aeronautics.
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an airplane or a hydroplane.
to take a plane to Dallas.
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a thin, flat or curved, extended section of an airplane or a hydroplane, affording a supporting surface.
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Architecture. a longitudinal section through the axis of a column.
adjective
verb (used without object)
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to glide or soar.
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(of a boat) to rise partly out of the water when moving at high speed.
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Informal. to fly or travel in an airplane.
We'll drive to Detroit and plane to Los Angeles.
noun
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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.
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a trowellike tool for smoothing the surface of clay in a brick mold.
verb (used with object)
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to smooth or dress with or as if with a plane or a planer.
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to remove by or as if by means of a plane (usually followed by away oroff ).
verb (used without object)
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to work with a plane.
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to function as a plane.
noun
noun
noun
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maths a flat surface in which a straight line joining any two of its points lies entirely on that surface
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a flat or level surface
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a level of existence, performance, attainment, etc
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short for aeroplane
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a wing or supporting surface of an aircraft or hydroplane
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adjective
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level or flat
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maths (of a curve, figure, etc) lying entirely in one plane
verb
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to fly without moving wings or using engines; glide
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(of a boat) to rise partly and skim over the water when moving at a certain speed
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to travel by aeroplane
noun
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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
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a flat tool, usually metal, for smoothing the surface of clay or plaster in a mould
verb
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to level, smooth, or cut (timber, wooden articles, etc) using a plane or similar tool
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(often foll by off) to remove using a plane
Usage
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.
Other Word Forms
Etymology
Origin of plane1
First recorded in 1400–50 plane 1 ( 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 plain 1; plane 1 ( 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 plain 1
Origin of plane2
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 plain 1; Middle English verb plane(n), plaine, pleine, from Middle French planer or directly from Late Latin plānāre
Origin of plane3
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)
Explanation
A plane is a vehicle that flies through the air, but it is also a tool used to make something smooth and flat, a kind of tree or a level surface. As a verb, to plane something is to make it flat and smooth. Don't confuse plane with plain, an adjective that means "simple" or a noun that means "flat land," like the plains of the American Midwest. This can be tricky because plane describes something that is flat and level, or the tool or action that makes something flat and level. If you remember that plain applies only to landforms, the difference will be plain to see — meaning obvious.
Vocabulary lists containing plane
The Best Starting Words for Wordle
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The SAT: Multiple-Meaning Words, List 8
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The New SAT: Multiple-Meaning Words
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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.
See Examples For:
Transported in specialised cold-water containers by truck and plane, the animals were accompanied throughout the journey by marine mammal veterinarians.
From BBC ● Jul. 22, 2026
They point out that “solar farm” is a misnomer because the land — an alluvial plane with Yucca colonies dating back hundreds of years, creosote rhizomatic rings even longer — will be scraped and fenced.
From Los Angeles Times ● Jul. 22, 2026
It had originally expected the plane in 2020, the airline’s president, Tim Clark, said.
From The Wall Street Journal ● Jul. 21, 2026
He insisted that the engine on the 18-year-old Boeing 737 plane had been fully serviced and overhauled in the past two years.
From BBC ● Jul. 21, 2026
I look at the plane more closely and sure enough, in the back seat is a wolf.
From "Woodsong" by Gary Paulsen
On Monday, planned engineering work in the West Midlands will further impact the "very limited" service planed between 08:00 and 18:00 BST, meaning some journeys will take longer.
From BBC ● Aug. 23, 2025
Through six editions now, their clear, planed prose has proved an essential reference for Angelenos in search of all the treasures that bejewel L.A.’s rumpled topography.
From Los Angeles Times ● Apr. 11, 2023
Every time we managed to summit a dune, following a sand ridge perfectly planed by the wind and sinking with each step, another beckoned us ahead.
From New York Times ● Feb. 27, 2023
Firefighters planed to use bulldozers to create fire lines protecting Wawona, she said.
From Seattle Times ● Jul. 10, 2022
He settled on the inner ash wood sill, leaning against the door jamb—cypress timber the skilled carpenter planed years ago and set up with a plumbline.
From "The Odyssey" by Homer
"Everybody is frustrated that we didn't get long planing runs," Carroll said on the slipway as Bluebird was towed back into the engineering tent for the final time.
From BBC ● May 17, 2026
Removal of the Cranach paintings’ cradles at some unknown date in history required a process of scraping and planing the back.
From Los Angeles Times ● Jan. 18, 2024
But children 16 and older can work in Wisconsin planing mills like the Florence Hardwoods facility where Shuls was pinned.
From Seattle Times ● Sep. 8, 2023
"We understand that the terrorists are planing new strikes. We know this for a fact," Zelenskiy said in his nightly video address.
From Reuters ● Nov. 27, 2022
Then with a planing tool, he carefully smoothed away the surface of the design so that the colored clay was completely level with the body of the vase itself.
From "A Single Shard" by Linda Sue Park
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.