in the ancient architecture, is a building where the columns stand very close to each other; only one diameter and a half of the column being allowed for the intercolumniations.

According to Mr Evelyn, the pycnostyle chiefly belonged to the Composite order, and was used in the most magnificent buildings; as at present in the peristyle at St Peter's at Rome, which consists of near 300 columns; and in such as yet remain of the ancients, among the ruins of Palmyra.