irritant

American  

[ir-i-tnt] / ˈɪr ɪ tnt /

adjective

1. tending to cause irritation; irritating. irritating.

---

noun

1. anything that irritates.

2. Physiology, Pathology. a biological, chemical, or physical agent that stimulates a characteristic function or elicits a response, especially an inflammatory response.

irritant British  

/ ˈɪrɪtənt /

adjective

1. causing irritation; irritating

---

noun

1. something irritant

Other Word Forms

• irritancy noun
• nonirritancy noun
• nonirritant adjective
• unirritant adjective

Etymology

Origin of irritant

1630–40; < Latin irrītant- (stem of irrītāns ), present participle of irrītāre to irritate; -ant

Compare meaning

How does irritant compare to similar and commonly confused words? Explore the most common comparisons:

• vesicant vs. irritant

Example Sentences

"It turns out that a specific irritant receptor is 30 times less sensitive in snow flies than in mosquitoes and fruit flies," Gallio said.

From Science Daily • Mar. 26, 2026

Video footage from witnesses showed Pretti holding his phone and filming agents before he was sprayed by a chemical irritant and taken to the ground by federal agents.

From Barron's • Jan. 28, 2026

Also an irritant for some locals: Most of the power will go to Tokyo.

From The Wall Street Journal • Dec. 28, 2025

But even if a sketch doesn’t quite work, you could rest in knowing its discomfort is temporary, with the irritant or foolishness changing every few minutes.

From Salon • Oct. 13, 2025

Doing otherwise would have been like failing to resign after losing a major piece in a chess tournament—a social irritant, a waste of time and resources.

From "1491" by Charles C. Mann