1) Vertigo is a feeling of movement, a sensation as if the external world were revolving around the patient (objective vertigo) or as if he himself were revolving in space (subjective vertigo). Vertigo is medically distinct from dizziness, lightheadedness, and unsteadiness.

2) A disordered state which is associated with various disorders (as of the inner ear) and in which the individual or the individual's surroundings seem to whirl dizzily.