trepidationn.[F. trpidation, 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.()()