Caoineadh is one of the oldest and most distinctive forms of Irish oral poetry, rooted in pre-Christian mourning practices and surviving vigorously into the eighteenth century. Performed typically by women, it combined improvised verse with ritual wailing, creating a genre at the intersection of poetry, song, and ceremony. Its most celebrated literary example is Eibhlín Dubh Ní Chonaill's lament for her husband Art O'Leary. The form influenced Anglo-Irish poets seeking authentic Gaelic emotional register, and its fierce, direct address to the dead gave later poets a model for grief that transcended sentimentality.

Caoineadh is the standard term for the Irish lament tradition, which was suppressed by colonial authorities who viewed it as barbaric. In poetry, it represents resistance to cultural erasure and the assertion of indigenous modes of expressing grief. The caoineadh allows for the expression of intense emotion that might otherwise be stifled, providing catharsis for the community. Modern poets often revive caoineadh forms to mourn historical traumas such as famine, emigration, or political violence, linking past and present suffering.