among the Greeks, was a long portico, open or covered at the top, where the athlete practised wrestling and running; the gladiators, who practised therein, were called xystici.

Among the Romans, the xystus was only an alley, or double row of trees, meeting like an arbour, and forming a shade to walk under.

Y.

YAW

YACHT, or YATCH, a vessel with one deck, carrying from four to twelve guns. See SHIP.