shadowcast noun 1verb 1forms 3 noun1 •The performance of a film by a group of amateurs at the same time as it is screened.They described shadowcasts where amateur performers acted out the film on a stage below the screen, and the whole audience had interacted, throwing objects and screaming things on cue. — 2013 verb1 •To take part in such a performance. formsshadowcasted · shadowcasting · shadowcasts