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

Now, in Minneapolis, CBP has come to rely heavily on sprays and other chemical irritants to push back protesters and observers. —Martin Kaste, NPR, 28 Jan. 2026

Pretti was fatally shot after trying to protect a woman who was violently shoved to the ground by an immigration agent also spraying chemical irritant. —Kevin Rector, Los Angeles Times, 28 Jan. 2026

Adjective

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

Pepper balls and pepper spray Pepper balls are a projectile fired from weapons that look like paintball guns, but the pellets marry the effects of a chemical irritant with the blunt force of a paintball. —Graham Hurley, CNN Money, 20 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