| A | B |
|---|
| above | upstage (as in the direction, "Cross above the sofa") |
| ad lib | fill in lines during a performance |
| amateur | one who works in the theatre without pay |
| amber | soft, yellow light used for stage lighting |
| anti-climax | an event noticeably less important than preceding event, often directly following the climax |
| apron | that part of the stage projecting in front of the curtain |
| Asbestos | fireproof curtain, located between stage and audience |
| aside | line to audience or other character, not noticed by other characters onstage |
| backstage | portion of the theatre not included in auditorium and stage proper |
| batten | movable pipe above the stage, used for hanging scenery |
| below | downstage of (as in "Cross below the sofa") |
| bit part | role with very few lines, if any, or little action |
| blank | mental fade-out causing lines or business to be forgotten |
| blend | actors move closer together, close gaps |
| board | diagram of theatre seating plan, used in a box office |
| bomb | theatrical dud |
| book | play manuscript |
| booking | to hire companies or actors |
| border light | strip of reflectors to light stage from overhead |
| build | to bring a scene to a climax by increasing volume, emphasis, pace, or intensity |
| Burlesque | exaggerated acting, often referred to as "ham". |
| business | stage action |
| byplay | stage action that helps to characterize, usually side action or mannerisms |
| call | warning to actors to be ready for entrance |
| call board | bulletin board backstage on which are posted important notices for actors and |
