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

The Star Trek trilogy Quinto starred in costarred a cast that also included Chris Pine, Zoe Saldaña, the late Anton Yelchin, John Cho, Simon Pegg, and Karl Urban. —Raechal Shewfelt, Entertainment Weekly, 28 Oct. 2025

The film, which is Sweden’s Oscar entry this year, is the final film in Saleh’s Cairo trilogy. —Melanie Goodfellow, Deadline, 27 Oct. 2025

Jarowskij/Yellow Bird is a high-end drama series producer best known internationally for its Millennium crime trilogy series, the original version of the The Girl With the Dragon Tattoo franchise. —Scott Roxborough, HollywoodReporter, 27 Oct. 2025

The earth-shattering events of the first trilogy have been all but forgotten, and the Magisterium looms as large as ever. —Lev Grossman, The Atlantic, 23 Oct. 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