A tool used to bore through rock when sinking shafts.

A surgical instrument used to remove a circular section of bone from the skull; a trephine.

To create a large hole by making a narrow groove outlining the shape of the hole and then removing the plug of material remaining by less expensive means.

To use a trepan; to trephine.

A trickster.

A snare; a trapan.

To ensnare; to seduce, to trick.