or Ditomum, in Roman antiquity, a tomb for two dead bodies, or the ashes of two. The ancients frequently buried two, three, or four bodies in the same sepulchre, disposed aside of each other; for it was held an impiety to lay one atop of another. Hence the sepulchres of the primitive Christians had the words bisomii, trisomii, quadrisomii, &c. inscribed on them, to indicate the number of bodies deposited in them.