irritation

Etymology

Borrowed from Middle French irritation, from Latin irrītātiō, from irrītāre, present active infinitive of irrītō (“I excite”).

noun

1. The act of irritating or annoying
   What irritation causes you to be so moody?
2. The state of being irritated
   Last spring, the periodical cicadas emerged across eastern North America. Their vast numbers and short above-ground life spans inspired awe and irritation in humans—and made for good meals for birds and small mammals. 2012 March-April, Anna Lena Phillips, “Sneaky Silk Moths”, in American Scientist, volume 100, number 2, page 172
3. A things or person that annoys
4. (physiology) a state of inflammation or painful reaction to allergy or cell-lining damage.
5. A 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.
   Hip pain is a common complaint in children and may indicate a very mild irritation in the hip joint or may be the symptom of a very severe abnormality 1975, Richard I. Feinbloom, Children's Hospital Medical Center, Child Health Encyclopedia: The Complete Guide for Parents