Terebra \Ter"e*bra\, n.; pl. E. {Terebras}, L. {Terebr[ae]}. [L., a borer.] 1. (Zo["o]l.) A genus of marine gastropods having a long, tapering spire. They belong to the Toxoglossa. Called also {auger shell}. 2. (Zo["o]l.) The boring ovipositor of a hymenopterous insect.