1540s, from Latin rostrum, the name of the platform stand for public speakers in the Forum in ancient Rome. It was decorated with the beaks of ships taken in the first naval victory of the Roman republic, over Antium, in 338 B.C.E., and the Latin word's older sense is "end of a ship's prow," literally "beak, muzzle, snout," originally "means of gnawing," an instrument noun from rodere "to gnaw" (see rodent). For the form, compare claustrum "lock, bar," from claudere "to shut." The extended sense, in reference to any platform for public speaking is attested by 1766. The classical plural is rostra.