tetralogy


tetralogy
tetralogy [te tral′ə jē]
n.
pl. tetralogies [Gr tetralogia: see TETRA- & -LOGY]
1. a series of four dramas, three tragic and one satirical, performed together at the ancient Athenian festival of Dionysus
2. any series of four related plays, novels, etc.

English World dictionary. . 2014.