Theatre Terms | AACT

Theatre Terms

image of question markAs a service to the theatre community, AACT provides over 1000 definitions of theatrical terms.  Fully searchable, our glossary is helpful for technical staff, directors, actors, producers, or anyone wanting to better understand the inner workings of theatre.

Click on a letter (A-Z) below to find terms beginning with the specified letter, OR enter a word in "Search for Term" OR search by entering a word in "Words in Definition." For example, entering the word "curtain" would display all words whose definition includes that word. (Note: If the A-Z or word search has been activated, it must be reset before using "Search for Term" or "Words in Definition." To reset the A-Z search: Click Here)

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Term Definition Link
L Abbreviation of left, meaning stage left, and seen in stage directions, either alone or in combination with other abbreviations, as in DSL(down stage left).
L.D. or LD Lighting Designer
LADDER Non-climbable structure in the shape of a ladder from which instruments can be hung in a vertical "stack."
LAMP 1) General term for unit of lighting equipment including spotlight, flood etc. 'Instrument' is more common in the U.S. (where 'lamp' often refers to what the uninitiated would call the 'bulb'), but both terms being replaced by the internationally recognized "luminaire." 2) A light source, but sometimes used to refer specifically to the "bulb" in a stage lighting instrument.
LASER Acronym for Light Amplification by Stimulated Emission of Radiation. A very high energy beam of light that remains virtually parallel throughout its length. Visible in the air only when a haze of smoke or dust is introduced. Great care is required when using lasers as this energy can cause permanent damage to the retina of the eye.
LASH To pull two flats together, edge to edge, by winding a lash line over lash line cleats in back.
LASH LINE A rope line used to fasten flats or other scenic units to one another.
LASH LINE CLEAT A small metal piece that can be screwed into the back of a flat frame, with a projecting tip over which a lash line can be slipped.
LAUGH LINE A line of dialogue that is calculated to produce a laugh from the audience.
LAVALIER MICROPHONE Originally, a mic worn around the neck on a string. Now applies to a small "tieclip" microphone.
LAY 'EM IN THE AISLES To make an audience laugh hysterically. Thus, said of a show or performer who is successful in the effort to be funny.
LAY AN EGG Said of a production or performance that fails miserably. Sometimes said of an actor whose jokes or funny business falls flat.
LC or L.C. Abbreviation of left center.
LEAD A principal role; also an actor who plays a principal role.
LEADER TAPE (Now mostly obsolete) Non-magnetic plastic tape used to begin and end sound tapes and to separate cues on reel-to-reel tape. Clear leader tape is used to activate the automatic stop on some playback machines. Leader tape is available in a variety of colors.
LEAK To leak light; said when the crack between two flats lashed together lets light through, or when a lighting instrument's beam is not properly channeled by barn doors or top hat.
LED A light-emitting diode (LED) offers many advantages over traditional light sources, including lower energy consumption, cool-running, longer lifetime, improved robustness, smaller size and faster switching. Applications of LEDs are diverse. They are used as low-energy indicators but also for replacements for traditional light sources in general lighting and theatre lighting, although they are still more expensive than traditional "bulbs."
LEG Drape set as masking piece at the side of the acting area. Usually set up in pairs across the stage and used in conjunction with borders to frame the audiences' view.
LEGITIMATE THEATRE Professionally produced stage plays as distinguished from films, variety shows, theme park performance.


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