magnum

noun

1. a large wine bottle having a capacity of two ordinary bottles or 1.5 liters (1.6 quarts).
2. a magnum cartridge or firearm.

adjective

3. (of a cartridge) equipped with a larger charge than other cartridges of the same size.
4. (of a firearm) using such a cartridge.
5. Informal. unusually great in power or size: a magnum spotlight; a magnum dosage.

noun plural -nums

1. a wine bottle holding the equivalent of two normal bottles (approximately 52 fluid ounces)

n.1788, “bottle containing two quarts of wine or spirits,” from Latin magnum, neuter of magnus “great in size” (see magnate). Registered 1935 by Smith & Wesson Inc., of Springfield, Massachusetts, as the name of a powerful type of handgun.