To be affected with slight, quick, and continued vibratory movements; be moved in a quivering manner by some external force.To be affected with involuntary muscular agitation; be agitated convulsively from either a physical or a moral cause; be in a tremor; quake; shake: as, to tremble with fatigue; his hand trembled from excitement.To feel or manifest a quivering agitation; be tremulous or shaky; quiver; quaver: as, his voice trembled from emotion.Figuratively, to be in doubt or suspense; oscillate between certainty and uncertainty; hang upon chance.n. The act or state of trembling; an involuntary quivering or shivering as from cold or fear.n. plural A form of disease or diseased condition in man or animals, characterized by continued trembling or tremulousness; specifically, in some parts of the United States, a disease of domestic animals, under peculiar local conditions, affecting the quality of the milk and flesh, and known as milk-sickness when communicated through these to human beings. See milk-sickness.