noun Anxiety over the uncertain future or possible ill-occurrence.
I decided, with considerable trepidation, to let him drive my car without me.
noun An involuntary trembling, sometimes an effect of paralysis, but usually caused by terror or fear.
noun 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.