n. A lamelli-branch mollusk of the genus Teredo, family Teredinidæ; the ship-worm, T. navalis, conspicuous for the destruction which it occasions to ships and submerged wood, by perforating them in all directions in order to establish a habitation.n. [capitalized] [NL. (Linnæus, 1758).] The typical genus of Teredinidæ, including T. navalis, the common teredo or ship-worm. See def. 1. Also called Septaria.n. Any disease in plants produced by the boring of insects.