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.
Ir"ri*ta*tive (?), a. 1. Serving to excite or irritate; irritating; as,
an irritative agent.
2. Accompanied with, or produced by, increased action or irritation;
as, an irritative fever. E. Darwin.
Ir"ri*ta*to*ry (?), a. Exciting; producing irritation; irritating. [R.]
Hales.
Ir"ro*rate (?), v. t. [imp. & p. p. Irrorated (?); p. pr. & vb. n.
Irrorating.] [L. irroratus, p. p. of irrorare to bedew; pref. ir- in +
ros, roris, dew.] To sprinkle or moisten with dew; to bedew. [Obs.]
Ir"ro*rate (?), a. (Zoöl.) Covered with minute grains, appearing like
fine sand.
Ir`ro*ra"tion (?), n. [Cf. F. irroration.] The act of bedewing; the
state of being moistened with dew. [Obs.] Chambers.
Ir`ro*ta"tion*al (?), a. (Physics) Not rotatory; passing from one point
to another by a movement other than rotation; -- said of the movement
of parts of a liquid or yielding mass. Sir W. Thomson.
Ir*ru"bric*al (?), a. Contrary to the rubric; not rubrical.
Ir"ru*gate (?), v. t. [L. irrugatus, p. p. of irrugare to wrinkle.] To
wrinkle. [Obs.]
Ir*rupt"ed (?), a. [L. irruptus, p. p. of irrumpere to break in; pref.
ir- in + rumpere to break or burst. See Rupture.] Broken with violence.