| Lunation (n.) The period of a synodic revolution of the moon, or the time from one new moon to the next; varying in length, at different times, from about 29/ to 29/ days, the average length being 29 d., 12h., 44m., 2.9s. 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 |