April Fools Day

Also found in: Thesaurus, Acronyms, Encyclopedia, Wikipedia.

A′pril Fools'′ Day`

April 1, when jokes or tricks are traditionally played on the unsuspecting.
References in periodicals archive ?
But Poisson D' Avril is actually a French April Fools Day tradition, which involves kids attempting to attach a paper fish to a victim's back without being noticed.
Have you ever fallen victim to an April Fools Day prank?
April Fools Day robbers who thought they had got away with a big sack of cash from a restaurant raid ended up with masses of dough - bread rolls.
It is not April Fools Day until next week but Americans have said who they think is the biggest fool and it's Jacko by a long way.
April Fools Day is believed to have started in 1564 when King Charles IX of France adopted the Gregorian calendar, shifting New Year celebrations from April 1 to January 1.