(1):
(v. i.) To quaver or shake, as sound; to be tremulous; as the voice trembles.
(2):
(n.) An involuntary shaking or quivering.
(3):
(v. i.) To shake involuntarily, as with fear, cold, or weakness; to quake; to quiver; to shiver; to shudder; - said of a person or an animal.
(4):
(v. i.) To totter; to shake; - said of a thing.