[pla-toh or, especially Brit., plat-oh] 
noun, plural -teaus, -teaux [-tohz, -tohz] , verb, -teaued, -teau⋅ing.| 1. | a land area having a relatively level surface considerably raised above adjoining land on at least one side, and often cut by deep canyons. |
| 2. | a period or state of little or no growth or decline: to reach a plateau in one's career. |
| 3. | 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. |
| 4. | a flat stand, as for a centerpiece, sometimes extending the full length of a table. |
| 5. | to reach a state or level of little or no growth or decline, esp. to stop increasing or progressing; remain at a stable level of achievement; level off: After a period of uninterrupted growth, sales began to plateau. |
| 6. | to cause to remain at a stable level, esp. to prevent from rising or progressing: Rising inflation plateaued sales income. |
| pla·teau (plā-tō') n. pl. pla·teaus or pla·teaux (-tōz')
To reach a stable level; level off: "The tension seemed to grow by degrees, then it plateaued" (Tom Clancy). [French, from Old French platel, platter, from plat, flat; see plate.] |
| plateau (plā-tō') Pronunciation Key
An elevated, comparatively level expanse of land. Plateaus make up about 45 percent of the Earth's land surface. |
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