tetralogy

noun

1. a series of four related works (plays or operas or novels)
   Terjemahkan ke Indonesia sumber: wordnet30
2. A group or series of four dramatic pieces, three tragedies and one satyric, or comic, piece (or sometimes four tragedies), represented consequently on the Attic stage at the Dionysiac festival.
   Terjemahkan ke Indonesia sumber: webster1913