A cement having the color of the Portland stone of England, made by calcining an artificial mixture of carbonate of lime and clay, or sometimes certain natural limestones or chalky clays. It contains a large proportion of clay, and hardens under water. [ 1913 Webster ]
A yellowish-white calcareous freestone from the Isle of Portland in England, much used in building. [ 1913 Webster ]
A celebrated cinerary urn or vase found in the tomb of the Emperor Alexander Severus. It is owned by the Duke of Portland, and kept in the British Museum. [ 1913 Webster ]