(archaeology) Acrypt cut into rock, chalk, or a tree trunk, especially a coffin formed by placing stone slabs on edge and topping them with a horizontal slab or slabs.
2019, Alan Staniforth,Cleveland Way, page66:
A central stone slabcist containing the burial was surrounded by a circles of stones placed on edge, probably to represent the round house in which the deceased had lived.
R. J. Thomas, G. A. Bevan, P. J. Donovan, A. Hawke et al., editors (1950–present), “cist”, inGeiriadur Prifysgol Cymru Online (in Welsh), University of Wales Centre for Advanced Welsh & Celtic Studies