Mawson, C.O.S., ed. (1870–1938). Roget’s International Thesaurus. 1922.

Class III. Words Relating to Matter
Section II. Inorganic Matter
2. Fluid Matter
2. Specific Fluids

344. Plain.

   NOUN:PLAIN, table-land, face of the country; open -, champaign-country; basin, downs, waste, weary waste, desert, wild, steppe, tundra, peneplain, pampas, savanna, prairie (grassland) [See Vegetable]; heath, common, wold, veldt or veld, moor, moorland; bush; plateau (level) [See Horizontality]; campagna [obs. as Eng.], champaign, uplands, fell [Brit.]; reach, stretch, expanse; alkali flat, llano; mesa, mesilla [U. S.], playa [Sp.]; shaking -, trembling- prairie; vega [Sp. Amer.].
  MEADOW, mead, haugh [Scot. & dial. Eng.], pasture, lea, ley or lay [dial.], pasturage, field.
  LAWN, green, plat, plot, grassplat.
  GREENSWARD, sward, turf, sod, grass; heather.
  GROUNDS; maidan [India], park, common, campus [U. S.], agostadero [Sp.].
   ADJECTIVE:CHAMPAIGN, campestral, campestrial [obs.], campestrian, campestrine.
  ALLUVIAL, fluvio-marine.
   ADVERB:in the bush.