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

Speaking of what’s kosher to talk about in regards to 28 Years Later…: There’s had been rumors that Cillian Murphy’s Jim would make an appearance in this new film, thus connecting this final trilogy entry to its ground-zero starting point. —David Fear, Rolling Stone, 21 June 2025

With death also comes life, and humanity is the throughline of the planned trilogy, set to continue with the forthcoming sequel 28 Years Later: The Bone Temple. —EW.com, 20 June 2025

Boyle and Garland took more of a backseat role as producers in the second installment of the series, 28 Weeks Later, but in January, The Hollywood Reporter confirmed the duo would be returning for what would mark the start of an entirely new trilogy. —Rachel Flynn, People.com, 19 June 2025

This potential trilogy is off to a solid — if not spectacular — start, though more bite would have been welcome. —Mark Meszoros, Boston Herald, 19 June 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