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.

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.

to cause to remain at a stable level, esp. to prevent from rising or progressing

Rising inflation plateaued sales income.

noun

elevation , highland , mesa , plain , stage , table , tableland , upland , milestone , table-land , uplands