irritant

1 of 2

noun

ir·​ri·​tant ˈir-ə-tənt 

: something that irritates or excites

irritant

2 of 2

adjective

: causing irritation

specifically : tending to produce physical irritation

Synonyms of irritant

Noun

• headache
• nuisance
• thorn
• frustration
• annoyance

Examples of irritant in a Sentence

Noun

dust and other lung irritants

The delay was a minor irritant.

Recent Examples on the Web

Noun

The judge issued restrictions that include barring agents from using chemical irritants. —Michael Loria, USA Today, 4 Feb. 2026

Other agents attempt to disperse the crowd from the area and eventually deployed chemical irritants, leaving the area clouded with many people coughing. —Sophia Peyser, CNN Money, 2 Feb. 2026

Adjective

One of the youths had restrictions due to a disability, medical or mental health issue that should have prohibited officers from using the chemical irritant on him. —Jason Henry, Daily News, 1 Feb. 2026

Now everyone has chemical irritant in their eyes. —Anna Schecter, CBS News, 28 Jan. 2026

Word History

First Known Use

Noun

1802, in the meaning defined above

Adjective

1636, in the meaning defined above

Kids Definition

irritant

1 of 2 adjective

ir·​ri·​tant ˈir-ə-tənt 

: tending to produce anger, annoyance, impatience, soreness, or inflammation

especially : tending to produce physical irritation

irritant

2 of 2 noun

: something that irritates

Medical Definition

irritant

1 of 2 adjective

ir·​ri·​tant ˈir-ə-tənt 

: causing irritation

specifically : tending to produce inflammation

irritant

2 of 2 noun

: something that irritates or excites

specifically : an agent by which irritation is produced

a chemical irritant