1. (n.) A state of terror or alarm; fear; confusion; fright\; as, the men were in great trepidation.

2. (n.) An involuntary trembling, sometimes an effect of paralysis, but usually caused by terror or fear; quaking; quivering.

3. (n.) 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.

agitation alarm apprehensiveness attack of nerves bluster bobbery boil boiling brouhaha buck fever bustle case of nerves chills of fear churn cold creeps cold shivers cold sweat commotion consternation conturbation creeps didder discomposure dismay disorder disquiet disquietude disturbance dithers dread ebullition embroilment excessive irritability excitement fear fear and trembling ferment fermentation fever feverishness fidgetiness fidgets flap flurry fluster flutter flutteration foment fright fume fuss goose bumps gooseflesh heartquake heaving horripilation horror hubbub hurly-burly inquietude jimjams jitters jumpiness maelstrom malaise moil morbid excitability nerves nerviness nervosity nervous stomach nervousness palpitation panic panickiness panting perturbation pitapat pitter-patter quaking quaver quavering quiver quiver of terror quivering restlessness roil rout row seethe seething shakes shaking shiver shivers shudder spell of nerves stage fright state of nerves stir sweat swirl terror thrill of fear throb throbbing tic to-do tremble trembling tremor trepidity tumult tumultuation turbidity turbulence turmoil twitching twitter unease uneasiness unrest upset vellication