Definitions
1.NounThe act of irritating or annoying."What irritation causes you to be so moody?"
2.NounThe state of being irritated.
3.NounA thing or person that annoys.
4.NounA state of inflammation or of painful reaction to cell or tissue damage.
5.NounA condition of morbid excitability or oversensitiveness of an organ or part of the body; a state in which the application of ordinary stimuli produces pain or excessive or vitiated action.