Plains Name Generator

Every grassland culture has its own word for open flat country, and real plains names almost always carry one. English uses Plain, Prairie, Downs, Moor, Heath, Fen, Vale and Flats; Spanish America has Pampa, Llano and Campo; Portuguese Brazil has Campos and Cerrado; Southern Africa has Veld and -vlakte; Central Asia has Steppe, Dala and Tal; Hungary has Puszta; France has Plaine and Landes; Germany has Heide and Börde. The word in front is usually practical: a river (Snake River Plain), a grass (Bluestem Prairie, Spinifex Plain), a soil colour (Black Earth Plain), an animal (Antelope Prairie, Plain of the Aurochs) or a nearby town (Salisbury Plain, Canterbury Plains).

Older and literary names use the 'Plain of X' and 'Fields of X' shapes: Plain of Jars, Plain of Marathon, Plains of Abraham, Fields of Asphodel. Those feel ancient and mythic, which is why fantasy maps lean on them (Plain of Falling Stars, Fields of Ruin). Invented compounds like Sunmarch, Gallowmoor or Windshear Plain work because they copy the structure of real English place names: one hard noun plus a form-word.

For worldbuilding, vary the form-word across your map. A continent where every flat region is called 'the X Plains' reads as generated; one with a Veld, some Downs, a Steppe and one legendary Plain of Bones reads as lived in.