Definition of: plateau

(pla·tō′, esp. Brit, plat′ō) noun plural ·teaus or ·teaux (-tōz′)
1. An extensive stretch of elevated and comparatively level land; tableland; mesa.
2. A broad, low stand for table decorations; also, a decorative plaque.
3. Psychol. A relatively level portion in the curve indicating a subject's rate of learning; also, the condition it typifies.
4. Mil. A device for making a rough preliminary setting on certain gun sights. [<F <OF platel a flat piece of metal or wood, orig. dim. of plat. See PLATE.]