Obs. rare. [a. OF. chaston, mod.F. chaton = It. castone, in same sense: the same word as OHG. chasto, mod.G. kasten chest, coffer, box; but their mutual relations and ultimate source are uncertain.] The broad part of a ring in which the stone is set; the collet.
1604. E. G[rimstone], D’Acosta’s Hist. Indies, V. ix. 353. A looking glasse of golde, shining and well burnished…. They called this glasse or chaston of golde Irlacheaya.
