An extensive, grassy, treeless or nearly-treeless plain.
Synonymous with prairie, as far as I can tell...except that each tends to be used only for certain regions.
'Llano' is mostly used in reference to areas in South America or southwestern United States;
'prairie' tends to refer to an area in central North America or the MIssissippi valley.
Los Llanos is a plain in northwestern South America.
Llano Estacado is a plain in the southwestern United States.
Etymology: 1600s, from Spanish llano, plain, level, even.
