irritant Meaning, Definition & Usage

  1. noun something that causes irritation and annoyance
    thorn.
    • he's a thorn in my flesh

WordNet

Ir"ri*tant adjective
Etymology
LL. irritants, -antis, p. pr. of irritare to make null, fr. L. irritus void; pref. ir- not + ratus established.
Definitions
  1. (Scots Law) Rendering null and void; conditionally invalidating.
    The states elected Harry, Duke of Anjou, for their king, with this clause irritant; that, if he did violate any part of his oath, the people should owe him no allegiance. Hayward.
Ir"ri*tant adjective
Etymology
L. irritans, -antis, p. pr. of irritare: cf. F. irritant. See Irritate to excite.
Definitions
  1. Irritating; producing irritation or inflammation.
Ir"ri*tant noun
Etymology
Cf. F. irritant.
Definitions
  1. That which irritates or excites.
  2. (Physiol. & Med.) Any agent by which irritation is produced; as, a chemical irritant; a mechanical or electrical irritant.
  3. (Toxicology) A poison that produces inflammation.

Webster 1913