Pronunciation: (ul'sur), [key]
1. Pathol.a sore on the skin or a mucous membrane, accompanied by the disintegration of tissue, the formation of pus, etc.
2. See peptic ulcer.
3. any chronically corrupting or disrupting condition, element, etc.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.