n. Among the ancient Romans, a defensive cover or screen which a body of troops formed by overlapping above their heads their oblong shields when in close array.n. A shelter similar in shape and design to the above, employed as a defense by miners and others when working in ground or rock which is liable to cave in.n. In medicine, an encysted tumor, which has been supposed to resemble the shell of a turtle. Also called talpa.n. [capitalized] In herpetology, the typical genus of Testudinidæ, of widely varying limits with different authors, and much confused with Cistudo.n. In anatomy, the fornix: more fully called testudo cerebri. See cerebrum.n. In ancient music, a species of lyre: so called in allusion to the lyre of Mercury, fabled to have been made of the shell of the sea-tortoise. The name was also extended in medieval music to the lute.