Is “Magnums” a Scrabble word?

1.A bottle of wine containing 1.5 liters of fluid, double the volume of a standard bottle.

2.A powerful firearm cartridge, often derived from a shorter, less powerful cartridge calibre that uses the same bullet.

3.A handgun that fires a cartridge of this calibre; chiefly a revolver, but rarely an autoloader firing an unusually powerful calibre.