Added 10 October 2026 halfmonth noun noun ! Definition from Wiktionary (CC BY-SA). More about halfmonth at Wordnik → Where our words come from → A period of time equal to half a month. A fortnight, a period of time equal to two weeks; fourteen days. Origin From half + month. From Wiktionary, via Kaikki.org (CC BY-SA) Related Words: half-yearhalf-hoursemimonthlymonthsemesterbimesterquadrimestermonthfulhalf-timehalfthtrimesterhalf-century Back to today's word