1. Rigging. noun. An assembly consisting of a sheave, axle, and housing, used to changed the direction of a line or to provide a mechanical advantage. Sometimes mistakenly called a pulley. 2. verb. To obstruct. "Don't let those cars block the loading dock." 3. verb. To plan traffic patterns and actor locations. "After break, we'll block Act II." (Some scenic designer once said this definition comes from the same as the previous, as the actors visually block the audience from seeing his extraordinarily beautiful designs. I believe he now works in the telemarketing field.) 4. Audio. noun. A specific frequency band or group for wireless devices. Wireless blocks are usually 25-50 MHz wide, though some systems use larger or smaller blocks. Generally speaking, wider blocks allow for more flexibility but increase the risk of RF interference. 5. Lighting, In a tracking lighting console a "block" cue stop all lights that are currently tracking through the cue stack.