Bedroom Farce
Production requiring varying states of undress and lots of doors.  Frequently chosen by play committee in the hope of recouping profits lost on the Autumn drama or "message play" (see below)

Blocking:
The art of moving actors across the stage in such a manner as not to collide with the walls, the furniture,  each other. Similar to playing chess, except that pawns don't argue back.

Blocking
Rehearsal that takes place early in production when cast are supposed to write down their moves on a script.  Largely known for the plaintive cries of "anyone here got a pencil"?

Bit Part (also known tactfully as "cameo role")
An opportunity for the actor with the smallest role to count everybody else's lines and mention repeatedly that he or she has the smallest part in the show.   

Director
The individual who suffers from the delusion that he or she is responsible for every moment of brilliance cited by the critic in the local review.  Also known as "God".

Dress Rehearsal
Rehearsal that becomes a whole new ball game as actors attempt to manoeuvre among the 49 objects that the set designer added at 7:30 that evening

Dry
That moment when you realise that everyone on stage is looking at your expectantly and you have no idea of your next line, where you are in the play or even what play you're in!

Eternity
The time that passes between a dry and the prompt

Forebrain
The part of an actors brain which contains lines, blocking and characterization

Hindbrain
The part of an actors brain that keeps up a running subtext in the background while the forebrain is trying to act; supplying a constant stream of unwanted information, such as who is sitting in the second row tonight, a reminder to seriously maim the crew member who thought it would be funny to put real Tabasco sauce in the fake Bloody Marys, or the fact that you need to go to Safeways on Sunday.

Green Room
Room shared by nervous actors waiting to go on stage and the precocious children whose  parents couldn't get a baby-sitter that night, a situation which can result in justifiable homicide.  Usually painted a rather dingy magnolia.

Message Play
Any play which its director describes as "worthwhile," "a challenge to actors and audience alike," or "designed to make the audience think." Usually played before a sparse audience made up of immediate members of the cast's family

Makeup Kit
(1) among experienced actors, a battered tackle box loaded with at least 10 shades of greasepaint in various stages of desiccation, tubes of lipstick and blush, assorted pencils, bobby pins, braids of crepe hair, liquid latex, old programs, jewellery, break-a-leg greeting cards from past shows, brushes and a handful of half-melted cough drops;
(2) for first-time male actors, a helpless look and anything they can borrow.

Panto
A peculiarly English tradition whereby three months of rehearsal precedes a week of improvisation

Stage Right, Stage Left
Two simple directions actors pretend not to understand in order to drive directors crazy. ("No, no, your OTHER stage right!")

Set
An obstacle course which, throughout the rehearsal period, defies the laws of physics by growing smaller week by week  while continuing to occupy the same amount of space

Stage Crew
Group of individuals who spend their evenings coping with 50-minute stretches of total boredom interspersed with 30-second bursts of mindless panic.

Stage Manager
Individual responsible for overseeing the crew, supervising the set changes, baby-sitting the actors and putting the director in a hammerlock to keep him from killing the actor who just decided to turn his walk-on part into a major role by doing magic tricks

The Tech 
The penultimate rehearsal when everything that was supposed to be done weeks before finally comes together at the last minute.   A period when the lighting director retreats to the bar and sulks, sound repeatedly blames music for moving his equipment, the cast stand around fidgeting and making loud comments about "professionalism" and the director has a nervous breakdown.   Also known as "Hell".  

Applause
A staccato sound made by members of the audience striking their hands together.  The reason why we all do it.
 

The Stage Manager steps up and says, "Right….I want  them both back in ten minutes."