Pampas Pam"pas, n. pl. [Sp., fr. Peruv. pampa a field, plain.] Vast plains in the central and southern part of the Argentine Republic in South America. The term is sometimes used in a wider sense for the plains extending from Bolivia to Southern Patagonia. Pampas cat (Zo["o]l.), a South American wild cat (Felis pajeros). It has oblique transverse bands of yellow or brown. It is about three and a half feet long. Called also straw cat. Pampas deer (Zo["o]l.), a small, reddish-brown, South American deer (Cervus, or Blastocerus, campestris). Pampas grass (Bot.), a very tall ornamental grass (Gynerium argenteum) with a silvery-white silky panicle. It is a native of the pampas of South America.