| Lustrum (n.) A lustration or purification, especially the purification of the whole Roman people, which was made by the censors once in five years. Hence: A period of five years. Thesaurus Entries abundant year, academic year, bissextile year, calendar month, calendar year, century, common year, day, decade, decennary, decennium, defective year, fiscal year, fortnight, hour, leap year, lunar month, lunar year, lunation, luster, lustrum, man-hour, microsecond, millennium, millisecond, minute, moment, month, moon, quarter, quinquennium, regular year, second, semester, session, sidereal year, solar year, sun, term, trimester, twelvemonth, week, weekday, year |