Pronunciation: (vur-tij'u-nus), [key]
1. whirling; spinning; rotary: vertiginous currents of air.
2. affected with vertigo; dizzy.
3. liable or threatening to cause vertigo: a vertiginous climb.
4. apt to change quickly; unstable: a vertiginous economy.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.