[pla-toh or, esp. British, plat-oh]

noun, plural pla·teaus, pla·teaux [pla-tohz or, esp. British, plat-ohz] /plæˈtoʊz or, esp. British, ˈplæt oʊz/.

a land area having a relatively level surface considerably raised above adjoining land on at least one side, and often cut by deep canyons.
a period or state of little or no growth or decline: to reach a plateau in one's career.
Psychology. a period of little or no apparent progress in an individual's learning, marked by an inability to increase speed, reduce number of errors, etc., and indicated by a horizontal stretch in a learning curve or graph.
a flat stand, as for a centerpiece, sometimes extending the full length of a table.

verb (used without object), pla·teaued, pla·teau·ing.

to reach a state or level of little or no growth or decline, especially to stop increasing or progressing; remain at a stable level of achievement; level off: After a period of uninterrupted growth, sales began to plateau.

verb (used with object), pla·teaued, pla·teau·ing.

to cause to remain at a stable level, especially to prevent from rising or progressing: Rising inflation plateaued sales income.

Origin of plateau

1785–95; < French; Old French platel flat object, diminutive of plat plate1 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for plateaux

plain, elevation, highland, mesa, table, stage, tableland, upland

Examples from the Web for plateaux

Historical Examples of plateaux

  • Why did you not call me a bandit when I was at the Plateaux?

    The Hour and the Man

    Harriet Martineau

  • The hillsides as well as the plateaux are overgrown with dense vegetation.

  • Of course, plateaux of accumulation are not always formed of igneous rocks.

  • Further on are the mountains of Armenia, and the ark of Noah on one of its plateaux.

    Astronomical Myths

    John F. Blake

  • Some veins run straight along on the plateaux, the hills, or plains.

    De Re Metallica

    Georgius Agricola

British Dictionary definitions for plateaux


noun plural -eaus or -eaux (-əʊz)

a wide mainly level area of elevated land
a relatively long period of stability; levelling offthe rising prices reached a plateau

verb (intr)

to remain at a stable level for a relatively long period

Word Origin for plateau

C18: from French, from Old French platel something flat, from plat flat; see plate



a state of central Nigeria, formed in 1976 from part of Benue-Plateau State: tin mining. Capital: Jos. Pop: 3 178 712 (2006). Area: 30 913 sq km (11 936 sq miles)
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

Word Origin and History for plateaux



1796, "elevated tract of relatively level land," from French plateau "table-land," from Old French platel (12c.) "flat piece of metal, wood, etc.," diminutive of plat "flat surface or thing," noun use of adjective plat "flat, stretched out" (12c.), perhaps from Vulgar Latin *plattus, from Greek platys "flat, wide, broad" (see plaice). Meaning "stage at which no progress is apparent" is attested from 1897, originally in psychology of learning. In reference to sexual stimulation from 1960.



1952, from plateau (n.). Related: Plateaued; plateauing.

Online Etymology Dictionary, © 2010 Douglas Harper

plateaux in Science



An elevated, comparatively level expanse of land. Plateaus make up about 45 percent of the Earth's land surface.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.