not relevant; not applicable or pertinent: His lectures often stray to interesting but irrelevant subjects.
Law.(of evidence) having no probative value upon any issue in the case.
Pronunciation note The pronunciation of irrelevant/ɪˈrɛləvənt/Show Spelled[ih-rel-uh-vuhnt]Show IPA as /ɪˈrɛvələnt/[ih-rev-uh-luhnt] as if spelled irrevelant, is the result of metathesis, the transposition of two sounds, in this case, the /l/[l] and the /v/[v]Relevant, the base word, is occasionally subject to the same process. Analogy with words like prevalent and equivalent may play a role. A similar reordering of the /l/[l] and /v/[v] consonant sounds, althought not a strict one-to-one metathesis, can be heard for Calvary/ˈkælvəri/[kal-vuh-ree] when pronounced /ˈkævəlri/[kav-uhl-ree]. Here the transposition is reinforced by the existence of the familiar word cavalry.