1. Anti-hero--This is the modern day notion of the hero as a rogue or picaro, a grey character and not the pristine hero of the heroic ages. This is not to be confused with the villain, however e.g. the characters in William Burroughs's fiction.
2. Anagnorisis--A term used by Aristotle in Poetics. It means understanding or realization. This is the juncture when the tragic protagonist becomes at one with his tragic predicament, realizing his reversal of fate e.g. Macbeth's 'tomorrow and tomorrow' speech.
3. Aside---It is a kind of solo speech on stage where other characters are also there but the speaker either speaks to himself or to one other, with the others not hearing the words spoken.
4. Denoument---In the Freytag-triangle of plot, this is the falling action after the peak of action is reached in the climax.
5. Hamartia---It is the error of judgement of the tragic character that leads him to his tragic destiny.
6. Catharsis--- This is the emotional function of tragedy according to Aristotle. It is the process in which the experience of tragedy evokes and by evocation, neutralizes the emotions of pity and fear.
7. Comic Relief--- It is a phase of comic situation, exchanges or character-antics in a gloomy or serious or tragic body of work. It provides some relief thus. The porter-scene in Macbeth is an interesting example where the comic relief still does not create a real distraction.
8. Three Unities---These are the unities of time, place and action. It was not directly advocated by Aristotle in Poetics. He only referred to the unity of action, but the three unities were theorized by the Neo-classic revisiting of Poetics.
9. Masque---It is a particular kind of comic and satirical form of theatre in vogue in Elizabethan times, catering to the royalist court audience. Ben Jonson wrote quite a few of them.