noun, Pathology. 1. the accumulation of excessive ketones in the body, as in diabetic acidosis. Origin of ketosis. 1915-1920.
Climate zones of Africa, showing the ecological break between the hot desert climate of the Sahara Desert (red), the hot semi-arid climate of the Sahel (orange) and the tropical climate of Central and Western Africa (blue).
Sahara Desert. Of the deserts of the world, the Sahara Desert is the largest desert that falls into a sub-tropical climate. The Sahara covers most of northeastern Africa which is about 10% of the continent. It is nearly as large as the United States in terms of land area.