Trephine
Trephine (?; 277) , noun
[A dim. of 1st trepan: compare French tréphine.]
(Surgery) An instrument for trepanning, being an improvement on the trepan. It is a circular or cylindrical saw, with a handle like that of a gimlet, and a little sharp perforator called the center pin.
Trephine , transitive verb
To perforate with a trephine; to trepan.