Definition of "vlei"

The country thereabout was a succession of vleys or gulleys, then filled with excellent clear water, teeming with water-fowl.

1861, Charles John Andersson, Lake Ngami, chapter XXV, page 301

She remembered the pleasurable warm smell of the cow droppings […] as if the four-divided stomachs of the great oxen were filled with nothing but concentrated memories of hours of grazing along the water heavy vleis.

1952, Doris Lessing, Martha Quest, Panther, published 1974, page 59

Although rare, it takes an unearthly amount of rain to fill the Tsauchab River and penetrate the dune area, bringing water into the vlei. During these rare times, the vlei takes on a life of its own, much different than in the absence of water […]

2010, Jeremiah Allen, Namibia, Other Places Travel Guide, page 199