Pronunciation: (tril'u-jē), [key]
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.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.