- noun a residue from milk after the casein and most of the fat have been removed. Whey is used as pig feed.
- The translucent liquid which is formed when coagulated milk separates into a semi-solid portion (curds) and a liquid portion (whey). It contains most of the lactose of the milk and a small amount of protein and fat. Usually a waste product but sometimes boiled or acidified to separate more solids from which a kind of cheese is made.
- noun the watery liquid that separates from the solid part of milk when it turns sour or when enzymes are added in cheese making.