The Sahel is a semi-arid transitionary region between the Sahara desert and southern Africa. The word, which seems to have been borrowed in the late eighteenth century, derives from Arabic sahil, which meant "coast" or "shore". Originally, the term referred exclusively to the coastal area in present-day Mauritania and Senegal, but gradually it came to be extended to the entire area in Africa with a similar geographic makeup. Sahil, which has cognates in everything from Azerbaijani to Urdu, is also used in the Arabic name for the "Ivory Coast", sahil al-aj, and the word Swahili, which originally described the "coast-dwellers" of East Africa. It probably ultimately derives from a Proto-Semitic root like s-h-l, with a similar definition. According to Google NGrams, literary usage of the word Sahel rapidly increased in the 1970s before coming to a peak in 1983.
Adam Aleksic, a rising sophomore studying linguistics and government at Harvard University, has been described as the internet's sixth most famous etymologist. He also has disturbing interests in politics, vexillology, geography, board games, conlanging, and law.