trilogy

UK: /ˈtrɪlədʒi/ US: /ˈtrɪlədʒi/ ,(tril′ə jē)

Inflections of 'trilogy' (n): npl: trilogies

WordReference Random House Learner's Dictionary of American English © 2025

tril•o•gy /ˈtrɪlədʒi/   n. [countable] , pl. -gies. 

1. Literature a series or group of three plays, novels, etc., that are closely related in characters, theme, etc.:
   the Oresteian trilogy by Aeschylus.

See -log-.

WordReference Random House Unabridged Dictionary of American English © 2025

tril•o•gy  (tril′ə jē), n., pl. -gies. 

1. a series or group of three plays, novels, operas, etc., that, although individually complete, are closely related in theme, sequence, or the like.
2. (in ancient Greek drama) a series of three complete and usually related tragedies performed at the festival of Dionysus and forming a tetralogy with the satyr play.
3. a group of three related things.

• Greek trilogía. See tri-, -logy
• 1655–65

Collins Concise English Dictionary © HarperCollins Publishers::

trilogy / ˈtrɪlədʒɪ/ noun ( -gies)

1. a series of three related works, esp in literature, etc
2. (in ancient Greece) a series of three tragedies performed together at the Dionysian festivals

Etymology: 19th Century: from Greek trilogia; see tri-, -logy