n. Tremulous agitation; perturbation; alarm.n. A trembling of the limbs, as in paralytic affections.n. A vibratory motion; a vibration.n. In ancient astronomy, a libration of the eighth sphere, or a motion which the Ptolemaic system ascribes to the firmament to account for certain phenomena, especially precession, really due to motions of the axis of the earth.n. Synonyms Tremor, Emotion, etc. (see agitation), flutter, tremulousness, discomposure.