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 author is working on a seventh entry, called Unrivaled, which will cap off the Hollanov trilogy. —Natalie Oganesyan, Deadline, 11 Apr. 2026

Huang's interconnected sports romance trilogy, set within the English Premier League football world, includes novels The Striker, The Defender and The Keeper, the latter of which is due out this October. —Carly Tagen-Dye, PEOPLE, 9 Apr. 2026

Franz Schubert’s Piano Sonata in B-flat Major, the final work in a trilogy the composer completed two months before his death, comprises the other half of the evening’s program. —Randy McMullen, Mercury News, 9 Apr. 2026

The trilogy concluded on April 1 with Fagen scribbling an inscrutable equation on the car window until, again, taking a break to consult an invisible timepiece on his wrist. —Devon Ivie, Vulture, 7 Apr. 2026

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