To open out. The N.E.D. gives a nautical reference, 1644.
1834. Finally, it [the vault] flares upward, so that the edges of the arch lose themselves in the projecting face of the cliff, which here rises from a gravelly soil to the height of four hundred feet; smooth as if chiselled by an artist, and naked as death.—C. F. Hoffman, ‘A Winter in the Far West,’ ii. 246 (Lond., 1835). (Italics in the original.)
