An Etymological Dictionary of Astronomy and Astrophysics

A black amorphous substance produced by heating wood or other natural organic matter
in the absence of air. It is used as a fuel.

Etymology (EN): M.E. charcole, maybe from cherre “char” + cole, → coal.

Etymology (PE): Zoqâl “live coal, charcoal,” variant sokâr; Sogd. askâr; Pashto skor-; Khotanese skara, probably ultimately from Proto-Ir. *uz-gar-, from *uz- “out,” → ex-, + *gar “to heat, kindle fire, cook;” cf. Tabari kalə “furnace,” kəlen “ash;” Laki koira; Kurd. kulan, kulandan “to cook;”
related to garm “warm;” cf. Skt. ghar- “to burn,” PIE root *gwher- “to warm, be warm,” → warm.