Antiq. Obs. [ad. L. exōstra, a. Gr. ἔξωστρα (f. ἐξ (see EX- pref.2) + ὠθέειν to thrust).] A hanging bridge anciently used by besiegers; also (see quot. from Blount).
1569. J. Sanford, trans. Agrippa’s Van. Artes, 33 b. Ye engins called … Exosters.
1656–81. Blount, Glossogr., Exoster, an ancient Engine for war; now used for a Petard to blow open a Port or Gate.
1692–1732. in Coles.
