'Plaistow' is either a 'place for playing' or the village of the de Plaiz family.
It appears as Playstowe in the Patent Rolls of 1414. Some derive it from Old English pleg, play, and stowe, place, perhaps where miracle plays were performed. Others link it to Sir Hugh de Plaiz, whose wife Philippa de Montfitchet owned the district and is reputed to have named it the Manor of Plaiz. Locals say 'Plahr-stow', not 'Play-stow'.