Old English sot, from Proto-Germanic *sotam "soot" (cf. Old Norse sot, Old Dutch soet, North Frisian sutt), literally "what settles," from PIE *sodo- (cf. Old Church Slavonic sazda, Lithuanian suodziai, Old Irish suide, Breton huzel "soot"), from root *sod-/*sed- "to sit" (see sedentary).
