Definition of "kloof"

Forming the south boundary of the valley is a range of disrupted bushy hills, with intervening deep and rugged kloofs and ravines, which constituted the retreat of Jan Pockbaas and his rebel banditti.

1901, William Thomas Black, The Fish River bush, South Africa, and its wild animals

The grass is rich and matted, you cannot see the soil. It holds the rain and the mist, and they seep into the ground, feeding the streams in every kloof.

1948, Alan Paton, chapter 1, in Cry, the Beloved Country, New York: Scribner, published 1987

Occasionally the narrow dirt road rose above the mist on the slopes of the high round hills, from where one looked down on the silver clouds in the valleys and kloofs below, a magical, incredible sight.

1978, André Brink, Rumours of Rain, Vintage, published 2000, page 172