Armageddon

noun2

1. •
   A catastrophic or great conflict, especially one regarded as likely to destroy the human race or the world; (loosely) the end of the world.

   • I shall know that your good is mine: ye shall feel that my strength is yours: / In that day of Armageddon, at the last great fight of all, / That Our Home stand together and the pillars do not fall. — 1896
2. •
   [before a noun] A type of chess game, usually played when a match would otherwise end in a draw, where black wins drawn games and white is given more time as compensation.