aithrí, f. (gs. ~).1. Penance. ~ a dhéanamh i bpeacaí, to do penance for sins. Breithiúnas ~ a dhéanamh, a chomhlíonadh, to perform (imposed) penance. Tá sé ag cur de a bhreithiúnas ~ (ar an saol seo), he is suffering, has a hard life. Sailm ~, penitential psalms. Sacraimint na h~, sacrament of penance. (As vn.)Ag ~, doing penance. 2. Repentance. Ré ~, time to repent; time to change one’s mind. Níl an ~ mhall maith; ní hé am na hola am na h~, late repentance is not good. ~ thoirní, sudden repentance. Tá sé ar fhód na h~ fós, he is still in this vale of tears.