\Tre*phine"\ (?; 277), n. [A dim. of 1st trepan: cf. F.
tr['e]phine.] (Surg.)
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.

\Tre*phine"\, v. t. [imp. & p. p. {Trephined}; p. pr. &
vb. n. {Trephining}.]
To perforate with a trephine; to trepan.