A surgical instrument with a cylindrical blade used to remove a circular section of tissue, f.e. bone or cornea; a trepan.
To use a trephine during surgery.
To perforate with a trephine.
A rotating cutting tool, used for cutting holes in rigid materials, that consists of an essentially conical point, relieved and fluted to form cutting lips, and spiral flutes which direct the chips away from the lips and toward ejection from the hole.