in Architecture, an arched roof, so contrived that the stones which form it sustain each other. Vaults are on many occasions to be preferred to soffits or flat ceilings, as they give a greater height and elevation, and are besides more firm and durable.

VAVAO or VAVON, one of the Friendly islands, in the South Pacific ocean, seen by Perouse in 1787. It is nearly equal to the size of Tongataboo. Lat. of the western point 18° 34' S.