trilogy

noun

tril·​o·​gy ˈtri-lə-jē 

plural trilogies

: a series of three dramas or literary works or sometimes three musical compositions that are closely related and develop a single theme

Did you know?

Dozens of tragic trilogies were written for the Greek stage, though only one, Aeschylus's great Oresteia (consisting of Agamemnon, The Libation Bearers, *and *The Eumenides), has survived complete. Authors in later years have occasionally chosen to create trilogies to allow themselves to develop a highly complex story or cover a long span of time. Tolkien's Lord of the Rings wasn't actually intended as a trilogy, but since it was published in three volumes it's usually called one. George Lucas's three original Star Wars movies are an example of a film trilogy (which he followed many years later by another).

Examples of trilogy in a Sentence

the last book in the trilogy

Recent Examples on the Web

Still, the film still has a ways to go to beat Chris Pratt and Bryce Dallas Howard’s sequel trilogy, each of which grossed $1 billion globally. —Monica Mercuri, Forbes.com, 5 Aug. 2025

While the stories were nothing to write home about, fans really appreciated how they were woven into the events of the original trilogy, expanding on iconic battles and off-camera events while also showing us the unseen side of the Galactic Civil War. —Fran Ruiz, Space.com, 4 Aug. 2025

Silo season 3 will be based on the second book in Howey’s trilogy, Shift. —Audrey Schmidt, People.com, 3 Aug. 2025

In general, what was your philosophy regarding callbacks and references to the original trilogy? —Brian Davids, HollywoodReporter, 1 Aug. 2025

Word History

Etymology

Greek trilogia, from tri- + -logia -logy

First Known Use

circa 1661, in the meaning defined above

Kids Definition

trilogy

noun

tril·​o·​gy ˈtril-ə-jē 

plural trilogies

: a series of three literary, dramatic, or musical works that are closely related and develop a single theme