Word Study
lunation
CIDE DICTIONARY
lunation, n. [Cf. Lunated.].
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 291913 Webster]
OXFORD DICTIONARY
lunation, n. the interval between new moons, about 291/2 days.
Etymology
ME f. med.L lunatio (as LUNATIC)
ROGET THESAURUS
lunation
Period
N period, age, era, second, minute, hour, day, week, month, quarter, year, decade, decenniumm lustrum, quinquennium, lifetime, generation, epoch, ghurry, lunation, moon, century, millennium, annus magnus, horary, hourly, annual.For further exploring for "lunation" in Webster Dictionary Online