n. dregs; the wash given to swin or cows; hogwash or waste matter
the GNU version of the Collaborative International Dictionary of English
n. Refuse; lees; dregs; the wash given to swine or cows; hogwash; waste matter.
The Century Dictionary and Cyclopedia
n. Refuse; lees; dregs; the wash or swill given to swine; specifically, the refuse of malt which has been used in brewing or distilling, given to swine and cows. Also called brewers' grains.
Word Usage
"They combined pot ale - the liquid from copper stills distillery equipment - and the spent grains used to make whisky, also known as draff, to produce butanol."