Theater glossary Because theater terms are specific to their own world a separate glossary is required. Some of the words do cross over with other types of shows but some are specific and have different meanings in theater. Advance bar: Lighting bar hung from the auditorium ceiling as opposed to over the stage to provide lighting from the front Ambient light: General indirect light from reflections or non-specific light sources Anchor: Fixing to stage floor, e.g. scenery Animation disc: Rotated in front of a light to create mov- ing effects such as clouds. May be called an `animated gobo' Apron: Part of the stage projecting into the main audito-