Trepan

A crown-saw or cylindrical saw for perforating the skull, turned, when used, like a bit or gimlet. See Trephine.

A kind of broad chisel for sinking shafts.

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.

A snare; a trapan.

a deceiver; a cheat.

To insnare; to trap; to trapan.