Architecture, a periphery of a circular figure; or a series of columns disposed in a circle, and insulated within side.

A Polystyle Colonnade, is that whose numbers of columns are too great to be taken in by the eye at a single view. Such is the colonnade of the palace of St Peter's at Rome, consisting of 284 columns of the Doric order, each above four feet and a half diameter, all in Tiberine marble.