a circle or ring (Lat. orbis), hence a globe or disk or other spherical object. It is thus used, chiefly poetically, of any of the heavenly bodies, including the earth itself (Lat. orbis terrarum), or of the eye-ball or eye. The "orb," also known as the "mound" (Lat. mundus, " world"), consisting of a globe surmounted by a cross, forms part of many regalia, being a symbol of sovereignty (see Regalia). In architecture the meaning to be attached to the word "orb" is doubtful. It is usually now taken to mean properly a blank or blind window, and thence a blank panel. If so the word represents Lat. orbus, " bereft of," "orphaned," fenestra orba luminis. It is also identified with a circular boss concealing the intersection of arches in a vault.