ir·ri·tant / ˈiritənt/ • n. a substance that causes slight inflammation or other discomfort to the body. ∎ fig. a thing that is continually annoying or distracting: in 1966, Vietnam was becoming an irritant to the government.• adj. causing slight inflammation or other discomfort to the body.DERIVATIVES: ir·ri·tan·cy n.

irritant (i-ri-tănt) n. any material that causes irritation of a tissue.