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

Diatomaceous earth is a lung and skin irritant, so always wear gloves, safety goggles, and a mask when applying it. —Lauren Landers, The Spruce, 10 Mar. 2026

Sánchez, by contrast, has at least been consistent, as well as a consistent irritant to Trump on multiple issues, including Greenland, relations with China and defense spending. —Tim Lister, CNN Money, 8 Mar. 2026

Adjective

Dark red markings on a gray panel, meanwhile, typically indicate that the ammunition contains an irritant or riot-control agent. —Bojan Stojkovski, Interesting Engineering, 8 Mar. 2026

Meanwhile, warmer conditions favor the formation of ground-level ozone, a heart and lung irritant. —Vijay Limaye, The Conversation, 12 Feb. 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