trepan

An instrument for boring; a borer.

The name given by the French to a boring-tool used for sinking wells and mining shafts to great depths and sometimes of great dimensions.

An instrument, in the form of a crown-saw, used by surgeons for removing parts of the bones of the skull, in order to relieve the brain from pressure or irritation. The trephine is an improved form of this instrument. See cuts under crown-saw and trephine.

To perforate by a trepan, especially by the surgical trepan; operate on with a trepan.

See trapan.

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.