Semi-weekly dates to 1791 (the prefix semi- meaning ‘ half ’) and biweekly to 1865 (the prefix bi- meaning ‘ two ’). Fortnight is a seventeenth-century contraction of the Middle English ‘ fourteniht ’, from the Old English ‘ feowertyne nigt ’ meaning ‘ fourteen nights ’. Fortnight definition: the space of fourteen nights and days ; two weeks.. See examples of FORTNIGHT used in a sentence. FORTNIGHT definition: 1. a period of two weeks: 2. a period of two weeks: 3. a period of two weeks. Learn more. Fortnight refers to a two-week duration , often used in various contexts, such as planning holidays, scheduling events, or measuring time intervals. While less commonly used in American English, it remains a standard term in British English and other English-speaking countries.
