From Longman Dictionary of Contemporary Englishfortnightfort‧night /ˈfɔːtnaɪt $ ˈfɔːrt-/ ●●○ S3 noun [countable usually singular] British English two weeks a fortnight’s holiday in a fortnight’s time a fortnight ago
Examples from the Corpus
fortnight• A package price of £700 for a fortnight is typical.• Hans was sent to Bournemouth for a fortnight.• And that's when Gooch will say farewell, having decided before the tour not to stay for the final fortnight.• Take a stroll in downtown Denver during rodeo fortnight.• Henry met and married this girl all in the course of one short fortnight.Origin fortnight Old English feowertyne niht “fourteen nights” 