The Collaborative International Dictionary of English v.0.48:
Dizziness \Diz"zi*ness\, n. [AS. dysigness folly. See Dizzy.] Giddiness; a whirling sensation in the head; vertigo. [1913 Webster]WordNet (r) 3.0 (2006):
dizziness n 1: a reeling sensation; a feeling that you are about to fall [syn: dizziness, giddiness, lightheadedness, vertigo]