<p><strong>Noun</strong></p><ul><li>a large wine bottle having a capacity of two ordinary bottles or 1.5 liters (1.6 quarts)</li><li>a magnum cartridge or firearm</li></ul><p><strong>Adjective</strong></p><ul><li>equipped with a larger charge than other cartridges of the same size (of a cartridge)</li><li>using such a cartridge (of a firearm)</li><li>unusually great in power or size: a magnum spotlight; a magnum dosage</li></ul>