Meaning

noun a fragment of incombustible matter left after a wood or coal or charcoal fire

originFrom Middle English cyndyr, syndir, synder, sinder, from Old English sinder (“cinder, dross, slag, scoria, dross of iron, impurity of metal”), from Proto-West Germanic *sindr, from Proto-Germanic *sindrą, *sindraz (“dross, cinder, slag”), from Proto-Indo-European *sendʰro- (“coagulating fluid, liquid slag, scale, cinder”). Cognate with Scots sinder (“ember, cinder”), West Frisian sindel, sintel…

Etymology from Wiktionary, CC BY-SA 3.0