Pronunciation: (i-rat'ik), [key]
1. deviating from the usual or proper course in conduct or opinion; eccentric; queer: erratic behavior.
2. having no certain or definite course; wandering; not fixed: erratic winds.
3. Geol.noting or pertaining to a boulder or the like carried by glacial ice and deposited some distance from its place of origin.
4. (of a lichen) having no attachment to the surface on which it grows.
1. an erratic or eccentric person.
2. Geol.an erratic boulder or the like.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.