Lustrum of wild beasts, plural lustra ( ), a den of vice. Lustrum A lustrum (, plural lustra) was a term for a five-year period in Ancient Rome. The lustration was originally a sacrifice for expiation and purification offered by one of the censors in the name of the Roman people at the close of the taking of the census. The sacrifice was often in the form of an animal sacrifice, known as a suovetaurilia. These censuses were taken at five-year intervals, thus a lustrum came to refer to the five-year inter-census period. ' (from ', ) is a lustration or
Lustrum of 24 days was interposed in every eleventh lustrum. It is highly probable that the recurrence of such a cycle or great year was, from the earliest times, solemnized with sacrifices and purifications, and that King Servius did not introduce them, but merely connected them with his census, and thus set the example for subsequent ages, which however, as we have seen, was not observed with regularity. The last lustrum was solemnized at Rome, in AD 74, in the reign of Vespasian. The word should not be confused with the identically spelled, but differently pronounced, lustrum ( ), a haunt