Pronunciation: (ir"i-tā'shun), [key]
1. the act of irritating or the state of being irritated.
2. something that irritates.
3. Physiol., Pathol.
a. the bringing of a bodily part or organ to an abnormally excited or sensitive condition.
b. the condition itself.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.