American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

[French, from Old French platel , platter , from plat , flat ; see plate .]

"The tension seemed to grow by degrees, then it plateaued"

To reach a stable level; level off: "The tension seemed to grow by degrees, then it plateaued" (Tom Clancy).

2. A relatively stable level, period, or state: Mortgage rates declined, then reached a plateau.

(Placename) 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)

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

to remain at a stable level for a relatively long period

2. a relatively long period of stability; levelling off: the rising prices reached a plateau .

pla•teau

(plæˈtoʊ; esp. Brit. ˈplæt oʊ)

(-ˈtoʊz, -toʊz)

1. a land area having a relatively level surface considerably raised above adjoining land on at least one side.

2. a period or state of little or no growth or decline, esp. one in which increase or progress ceases: to reach a plateau in one's career.

3. to reach a state or level of little or no growth or decline; stabilize.

platel flat object, diminutive of plat plate] [1785–95; < French; Old Frenchflat object, diminutive of

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