I. ˈmagnəm, ˈmaig- noun
( -s )
Etymology: Latin, neuter of magnus great — more at much
1. : a large wine bottle holding about 2/5 of a gallon
2.
[from Magnum, a trademark]
: a magnum cartridge or firearm
II. adjective
: high-powered due to a larger case and larger powder charge than other cartridges of approximately the same caliber — used of cartridges and of weapons designed to use the cartridges