Ring Cycle, say: unreasonably large, OTT, and ultimately lengthy

• A series of four related works (plays or operas or novels)

Wiktionary Word definitions in Wiktionary
n. 1 A set of four works of art that are connected, and that can be seen either as a single work or as four individual works. They are commonly found in literature, film, or video games. 2 (context medicine English) A combination of four symptoms.

Wikipedia Word definitions in Wikipedia
A tetralogy (from Greek τετρα- tetra- , "four" and -λογία -logia , "discourse") is a compound work that is made up of four distinct works. The name comes from the Attic theater , in which a tetralogy was a group of three tragedies followed by a satyr play ...

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
1650s, from Greek tetralogia , from tetra- (see tetra- ) + -logia (see -logy ). A group of four dramatic compositions, originally three tragedies (the trilogia ) and a Satyric play.

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Tetralogy \Te*tral"o*gy\, n. [Gr. ?; te`tra- (see Tetra- ) + ? a speech, discourse: cf. F. t['e]tralogie.] (Gr. Drama) A group or series of four dramatic pieces, three tragedies and one satyric, or comic, piece (or sometimes four tragedies), represented ...

WordNet Word definitions in WordNet
n. a series of four related works (plays or operas or novels)