"sepulchral chest or chamber," 1804, in some cases from Latin cista "wickerwork basket, box," from Greek kiste "box, chest" (see chest); according to OED, in some cases from Welsh cist in cist faen "stone coffin," the first element of which is from the Latin word.
prehistoric European coffin containing a body or ashes, usually made of stone or a hollowed-out tree; also, a storage place for sacred objects. "Cist" has also been used in a more general sense to refer to the stone burial place itself, usually built in the form of a dolmen, with several upright stone slabs supporting a flat roofing stone