[noun] [C] [plural] UK plateaux or [US and ANZ] plateaus - a large flat area of land that is high above sea levelThe town is situated on a plateau high up amongst the mountains of the north.A plateau is also a period during which there are no large changes.The US death rate reached a plateau in the 1960s, before declining suddenly.
PLATEAU
Meaning of PLATEAU in English
Cambridge English vocab. Кембриджский английский словарь. 2012