1) Photographic equipment 
A clapperboard is a device used in filmmaking and video production to assist in the synchronizing of picture and sound, and to designate and mark particular scenes and takes recorded during a production. The sharp `clap` noise that the clapperboard makes can be identified easily on the audio track, and the shutting of the clapstick can be identi.....
[n] - photographic equipment used to synchronize sound and motion picture
noun photographic equipment used to synchronize sound and motion picture; boards held in front of a movie camera are banged together