1. Gr. Antiq. A series of three tragedies (originally connected in subject), performed at Athens at the festival of Dionysus.
1836. Thirlwall, Greece, III. xviii. 73. A trilogy, which comprised three distinct tragedies.
1842. Brande, Dict. Sc., etc., s.v., All the plays of Æschylus, and the Henry VI of Shakspeare, are examples of a trilogy.
1850. Grote, Greece, II. lxvii. (1862), VI. 25. To three serious dramas or a trilogy … the tragic poet added a fourth or satyrical drama.
2. Any series or group of three related dramatic or other literary works.
1661. Blount, Glossogr. (ed. 2), Trilogie,… a speaking or writing in three parts.
1820. T. Mitchell, Aristoph., I. p. cxxvi. That immortal Trilogy of Plato, which has been embalmed by the tears of all ages.
1841. Trench, Parables, xxii. (1877), 376. These parables are thus a trilogy.
1875. Jowett, Plato (ed. 2), III. 679. The other great Platonic trilogy of the Sophist, Statesman, Philosopher.
1877. Dowden, Shaks. Prim., vi. 90. The trilogy consisting of I and II Henry IV and Henry V.
3. transf. and fig. A group of three related utterances, sayings, subjects, etc.
1835. T. Mitchell, Aristoph., Acharn., 249, note. What Theophrastus evidently intended for a trilogy of characters,… each rising above the other in want of shame and an absence of decency.
1837. Carlyle, Fr. Rev., III. I. v. Thus they three, in wondrous trilogy, or triple soliloquy.
1879. Farrar, St. Paul, I. 581, note. His fundamental trilogy of Christian virtues—faith, hope, love.
