- noun a device that allows you to make a light brighter or dimmer
- An electrical or mechanical device used to dim the lightingon stage. Early expedients included the use of currents of air toextinguish candles and placing opaque screens in front of the lights.The first electric dimmers consisted of metal plates immersed in barrelsof a brine solution (which apparently gave off a bad odour). In themodern theater a central computerized dimmer board is used, enablingthe operator to connect lights to dimmer switches in any requiredcombination (a practice known as patching). Memory controlscan also now be used to preset light levels in advance. see alsogrand master control.