I. (ˈ)pla|tō sometimes pləˈt- noun
( plural plateaus or plateaux -ōz)
Etymology: French, from Middle French, from plat flat — more at plate
1.
a.
(1) : a flat and often galleried ornamental dish or salver (as for a tea service or condiments)
(2) : an ornamental plaque
(3) : a table top ; especially : a removable and usually decorated top (as of marble or inlay)
(4) : an ornamental shelf (as in a whatnot)
b. : a woman's hat of a flat or plate-shaped style
2.
a. : a usually extensive land area having a relatively level surface raised sharply above adjacent land on at least one side and often dissected by canyons : tableland
the Columbia lava plateau in eastern Washington and Oregon
the plateau region of central Bolivia
— compare mesa
b. : a similar undersea feature
3.
a. : a region of little or no change in the dependent variable of a graph ; especially : a horizontal section of a learning curve indicating neither progress nor decline
b. : a relatively stable level, period, or condition ; especially : one showing cessation or minimization of cyclical phenomena or of fluctuations up or down
a price plateau interrupting an inflationary spiral
output seems to have reached a plateau
II. adjective
Usage: usually capitalized
1. : anasazi
2. : of or relating to the Indians of the No. American plateau area between the Cascade mountains and the Rocky mountains south of the great bend of the Fraser river or to their seminomadic food-gathering culture
III. intransitive verb
( -ed/-ing/-s )
: to reach a period or phase of stability : form a plateau : level off
after initial logarithmic progress growth plateaued sharply