A game played by a group of (old or boring) people where you need to fill a certain pattern on a card with random numbers on it.
This pattern will be shown before the game starts; the game continues by drawing random numbers, until someone's card (the pattern) is complete.
Upon completion one screams "BINGO" to indicate the win, an observer will check if all the numbers where indeed drawn and claim the "BINGO" valid or a fraud.
If one game is complete a new pattern is picked and the game starts over.
In common language "Bingo" indicates a cheer of accomplisment, pretty much used like "Bulls-eye".