Dionysia is a festival held in Athens, which includes a tragedy competition. (See 'About Greek Theater' for more information).
Dramatic irony is a situation in which the characters on stage do not know something (or some of them do not know something) which the audience does know. Dramatic irony recurs throughout Oedipus - for instance, when the Messenger suggests that he never killed the young baby that Jocasta had given him, signifying that he clearly had grown up to become Oedipus the King. Oedipus, however, does not realize this until much later.
Oikos is the greek word for 'household' or 'house' - often used to mean 'bloodline' or 'family'. It is the opposite to 'polis'.
Polis is usually translated to 'city-state', but as well as literally referring to the city, it can also be the Greek word for 'citizenship', or 'body of citizens'.
The satyr play is the fourth, probably comic, play that would have been performed after a trilogy and written by the same author. The only surviving satyr play is Euripides' Cyclops.
A skene is the permanent stone building at the back of the stage in which costumes and props could be stored, and which served variously as the internal locations that the play might require (houses, tents, etc.).
Thebes is city in which the play is set and is often set up in classical literature as the 'other' or 'opposite' to Athens, where the City Dionysia took place.
Oedipus Rex or Oedipus the King Questions and Answers
The Question and Answer section for Oedipus Rex or Oedipus the King is a great
resource to ask questions, find answers, and discuss the novel.