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Webster 1913 Edition


Irritation

Irˊri-ta′tion

,
Noun.
[L.
irritatio
: cf. F.
irritation
.]
1.
The act of irritating, or exciting, or the state of being irritated; excitement; stimulation, usually of an undue and uncomfortable kind; especially, excitement of anger or passion; provocation; annoyance; anger.
The whole body of the arts and sciences composes one vast machinery for the
irritation
and development of the human intellect.
De Quincey.
2.
(Physiol.)
The act of exciting, or the condition of being excited to action, by stimulation; – as, the condition of an organ of sense, when its nerve is affected by some external body; esp., the act of exciting muscle fibers to contraction, by artificial stimulation;
as, the
irritation
of a motor nerve by electricity
; also, the condition of a muscle and nerve, under such stimulation.
3.
(Med.)
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.

Webster 1828 Edition


Irritation

IRRITA'TION

,
Noun.
The operation of exciting heat, action, and redness in the skin or flesh of living animals, by friction or other means.
1.
The excitement of action in the animal system by the application of food, medicines and the like.
2.
Excitement of anger or passion; provocation; exasperation; anger.
3.
In physiology, an exertion or change of some extreme part of the sensorium residing in the muscles or organs of sense, in consequence of the appulses of external bodies.
Irritation is the effect of a stimulus applied to an irritable part.