magnum opus

American  

noun

1. a great work, especially the chief work of a writer or artist.

   Proust's magnum opus is Remembrance of Things Past.

---

magnum opus British  

noun

1. a great work of art or literature, esp the greatest single work of an artist

---

magnum opus Cultural  

1. The most important work in a person's career, especially in literature, art, or scholarship: “Moby Dick was Melville's magnum opus.” From Latin, meaning “great work.”

---

Etymology

Origin of magnum opus

Borrowed into English from Latin around 1785–95

Example Sentences

In 1962, Macdonald published his magnum opus of cultural criticism, “Against the American Grain: Essays on the Effects of Mass Culture,” containing the most famous of his essays, “Masscult & Midcult.”

From Salon • Apr. 19, 2026

The following year Skepta released his own magnum opus, Konnichiwa.

From BBC • Oct. 31, 2025

I sank into Randy Carter’s comfy couch, excited to see the Hollywood veteran’s magnum opus.

From Los Angeles Times • Aug. 14, 2025

Consumers’ Research, the Supreme Court reversed an opinion that Oldham presented as something of a magnum opus.

From Slate • Jul. 10, 2025

It is the opening of John Keegan’s 1993 magnum opus, A History of Warfare: War is not the continuation of policy by other means.

From "The Sense of Style" by Steven Pinker