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Synonyms

magnum

American  
[mag-nuhm] / ˈmæg nəm /

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

  1. (of a cartridge) equipped with a larger charge than other cartridges of the same size.

  2. (of a firearm) using such a cartridge.

  3. Informal. unusually great in power or size.

    a magnum spotlight; a magnum dosage.
magnum British  
/ ˈmæɡnəm /

noun

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

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of magnum

1780–90; < Latin, neuter of magnus large; in reference to firearms, originally used as a trademark by the Smith and Wesson Co.

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

He was carrying 743 rounds of ammunition and four handguns – two 9mm Browning semi-automatic pistols and two Smith & Wesson .357 magnum revolvers.

From BBC • Mar. 7, 2026

After inspecting a gifted magnum of Chinese wine, he stressed that the country "knew how to produce" -- another worry for French producers.

From Barron's • Feb. 9, 2026

A tall, slender Riesling magnum is the giraffe of the wine world: striking and exotic.

From The Wall Street Journal • Dec. 22, 2025

The dictionary is Garner’s magnum opus, as essential to attorneys as Gray’s Anatomy is to physicians.

From Los Angeles Times • Oct. 30, 2025

“The point is, she is your magnum opus. Only a Pellinore can catch her. You have told us so often.”

From "The Once and Future King" by T. H. White

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.