A fortnight is fourteen nights — two weeks. This is a fancy, old-fashioned term you don't hear much anymore.

Fortnight is not a word we use very much in this country, unless you want to sound very British, very 19th century, or both. If you read old British novels, you'll read about a lot of fortnights, and the word is still in use in Great Britain and some former British colonies. It comes from the Old English, literally a shortened form of fourteen nights. People sometimes use it when they're discussing their vacations or their pay schedules. Here, we just say two weeks.

Definitions of fortnight

n a period of fourteen consecutive days

“most major tennis tournaments last a fortnight
two weeks
Type of:
period, period of time, time period
an amount of time

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