Bay

Arm of the sea. In engineering, span of a bridge, or a panel length in a tru ; used mostly in England.-A division or compartment of a building set off from the rest not by walls, but by columns or other detached structural members. In Gothic architecture, a bay is the part of a church bounded by columns or piers and covered with a single vault, or with a section of roof inclosed by principal rafters, and, if in an aisle or clerestory, lighted by a single opening or group of openings.