A pandy is another name for a fulling mill, and is used primarily in Wales.
Fulling is one of the processes in woollen clothmaking which involves the cleansing of cloth (particularly wool) to get rid of oils, dirt, and other impurities, and thickening it.
Fulling mills, from medieval times onwards, were often water powered. In these, the cloth was beaten with wooden hammers, known as fulling stocks. There were two kinds of fulling stocks, but in both cases the machinery was operated by cams on the shaft of a waterwheel or on a tappet wheel, which lifted the hammer.
