Tre*phine" (?; 277), n. [A dim. of 1st trepan: cf. F. tréphine.]
(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.
Trep"id (?), a. [L. trepidus.] Trembling; quaking. Thackeray.
Trep`i*da"tion (?), n. [F. trépidation, L. trepidatio, fr. trepidare to
hurry with alarm, to tremble, from trepidus agitated, disturbed,
alarmed; cf. trepit he turns, Gr. &?; to turn, E. torture.] 1. An
involuntary trembling, sometimes an effect of paralysis, but usually
caused by terror or fear; quaking; quivering.
2. Hence, a state of terror or alarm; fear; confusion; fright; as, the
men were in great trepidation.
3. (Anc. Astron.) A libration of the starry sphere in the Ptolemaic
system; a motion ascribed to the firmament, to account for certain
small changes in the position of the ecliptic and of the stars.
Syn. — Tremor; agitation; disturbance; fear.