lunar month
From Longman Dictionary of Contemporary EnglishRelated topics: Chronology, Astronomylunar monthˌlunar ˈmonth noun [countable] TMCHAa period of 28 or 29 days between one new moon and the nextExamples from the Corpuslunar month• The days passed quickly toward the end of the eighth lunar month.• By the time you are thirty, an entire lunar month later.