/pla toh"/ or, esp. Brit., /plat"oh/ , n. , pl. plateaus, plateaux /-tohz", -tohz/ , v. , plateaued, plateauing .
n.
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. Psychol. 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.
v.i.
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.
v.t.
6. to cause to remain at a stable level, esp. to prevent from rising or progressing: Rising inflation plateaued sales income.
[ 1785-95; platel flat object, dim. of plat PLATE 1 ]