agôn (plural: agônes): a formal debate between two characters with strongly opposing views
barbaros (plural: barbaroi): a non-Greek, often with the derogatory sense conveyed by the English ‘barbarian’
catharsis: the word Aristotle uses to describe the effect of watching tragedy, a kind of purgation of the emotions
chorêgos: the wealthy man who funded the chorus in a tragedy. This funding system is known as the chorêgia
deus ex machina: an appearance by a god, usually to resolve the situation at the end of a play. Especially common in Euripides
dithyramb: a type of choral poetry performed by a chorus of fifty
dysgenês: ill-bred (either in the sense of being low born, or in the sense of showing bad manners or rude behaviour)
ekkyklêma: a stage device used to show interior scenes, consisting of a platform on wheels
episode: a scene between actors in iambic dialogue
eugenês: well-bred (in the sense either of birth or of nobility of character): the opposite of dysgenês
hamartia: a mistake or error. According to Aristotle, it is important that tragic figures come to grief because of a mistake
mêchanê: a crane which enabled gods to appear as though flying above the stage
monody: a solo song performed by an actor
nomos: custom, law, convention
nothos: an illegitimate son
oikos: the household or family unit
paean: a choral song, usually performed in honour of Apollo
parodos: the entry-song performed by the chorus
peripeteia: Aristotle’s word for a reversal of fortune
physis: the nature or character of a person
polis: the Greek city-state
rhabdouchoi: ‘rod-holders’, the theatre-police who controlled the crowd at performances if they became too unruly
stasimon: (plural: stasima): an ode performed by the chorus