tĕrē̆bra, ae, f. (neutr. collat. form tĕ-rē̆brum, Hier. in Isa. 12, 44, 12 al.) [tero].
I An instrument for boring , a borer , an auger , gimlet , Cato R. R. 41, 3; Col. 4, 29, 15 sq.; Plin. 7, 56, 57, § 198; 17, 15, 25, § 116; 37, 13, 76, § 200.—
II As a surgical instrument, a trephine , Cels. 8, 3.—
III A military engine for boring through walls in sieges , Vitr. 10, 13, 7.