lūstrum ī, n 3 LV-, a purificatory sacrifice, expiatory offering, lustration (for the whole people by the censors at the end of their term of five years): lustrum condidit, made the lustral sacrifice: sub lustrum censeri, at the close of the census.

—A period of five years, lustrum: octavum, H.: hoc ipso lustro: superioris lustri reliqua.

— A period of four years (of the Julian calendar), O.