Sahel Syllabification: (Sa·hel)Pronunciation: /səˈhāl, -ˈhēl, -ˈhel/Definition of Sahel a vast semiarid region of North Africa, south of the Sahara, that forms a transitional zone between the desert and the region known as Sudan. Derivatives SahelianPronunciation: /-ēən/ adjective & noun Sahel in other Oxford dictionaries Definition of Sahel in the British & World English dictionary