- A boring tool - Medical tool - Shaftboring tool - Surgical instrument for excising pieces Of the Skull - 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.
- Boring tool - One who, or that which, reams; specifically, an instrument
with cutting or scraping edges, used, with a twisting motion, for
enlarging a round hole, as the bore of a cannon, etc.