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 tiny irritants Americans call chiggers are the larval stage of Trombiculidae mites. —Eva Flowe june 11, Charlotte Observer, 11 June 2026

The chemical is primarily a respiratory irritant. —Meredith Deliso, ABC News, 10 June 2026

Adjective

According to Jim McHale, president of JP McHale Pest Management, salt can act as an irritant or contact killer for pests with soft exoskeletons. —Olivia McIntosh, Martha Stewart, 6 June 2026

Ozone can also cause an irritant effect that makes people unable to take a deep breath. —Eva Flowe april 28, Charlotte Observer, 28 Apr. 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