Drainage basin: The area drained by a river and its tributaries. A drainage basin is considered to be an open system because water can be added or lost from a drainage basin.
Noun. 1. milk whey-the serum or watery part of milk that is separated from the curd in making cheese. whey. blood serum, serum-an amber, watery fluid, rich in proteins, that separates out when blood coagulates. 1  Facebook. 2  Twitter.
Whey protein is one of the two proteins found in milk, with the other being Casein Protein. When a coagulant (usually renin) is added to milk, the curds (casein) and whey separate. Whey protein is the water-soluble part of milk. Whey is used as a protein supplement.