1. (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.

2. (v. i.) To totter; to shake; -- said of a thing.

3. (v. i.) To quaver or shake, as sound; to be tremulous; as the voice trembles.

4. (n.) An involuntary shaking or quivering.