| Trepan 1. (n.) A crown-saw or cylindrical saw for perforating the skull, turned, when used, like a bit or gimlet. See Trephine. 2. (n.) A kind of broad chisel for sinking shafts. 3. (v. t. & i.) To perforate (the skull) with a trepan, so as to remove a portion of the bone, and thus relieve the brain from pressure or irritation; to perform an operation with the trepan. 4. (n.) A snare; a trapan. 5. (n.) a deceiver; a cheat. 6. (v. t.) To ensnare; to trap; to trapan. Thesaurus Entries aculeus, acumination, bit, bore, bore bit, borer, brace and bit, breast auger, breast drill, broach, burr, chamfer bit, corkscrew, cross bit, cusp, diamond drill, drill, drill press, gimlet, hand drill, keyway drill, mucro, neb, needle, nib, point, portable drill, posthole auger, power drill, prick, prickle, pump drill, ratchet drill, reamer, rotary drill, star drill, sting, strap drill, tap, tip, trepan, trephine, twist bit, twist drill, wimble |