The Latin meaning for "Great Work". Usually meaning the greatest, most popular, pinnacle, or most renowned achievement of an artist, artist or composer. Or a "masterpiece"
Songs for the Deaf is Queens of the Stone Age's magnum opus.

The Dark Knight is Christopher Nolan's magnum opus.
by Johnny Tentacles July 28, 2009
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1. A great work or achievement.

2. An inanimate object in Tower of Cone Mesh Climbing (Juke's Towers of Hell, Roblox) that falls down when you try to get on it, activating an object below. (also called, MY NEXT MAGNUM OPUS) Also, when jumping to it, it makes a loud "metal falling" sound.
Definition 1
Person 1: yo bro look at this magnum opus
Person 2: thats cool man

Definition 2
inanimate object: MY NEXT MAGNUM OPUS
player: *jumps to it*
inanimate object: *falls*
by MyNextMagnumOpus November 15, 2022
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Person 1: I will beat you with my Excalibur!
Person 2: Your penis is no match for my Magnum Opus!
by Soul_kai March 8, 2020
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The Magnum Opus is the highest working in Spiritual Satanism, and the end result of all legitimate occult disciplines, the allegories and the legends of the Gods.

The Magnum Opus is physical and spiritual perfection and immortality.
You are going to do Magnum Opus.
by RobyRoby August 7, 2018
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Ex 1: I had a huge magnum opus moment yesterday.
Ex 2: The song it’s raining tacos is a real Magnum opus moment
by Cronchy Craker October 16, 2019
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