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.
WebMD indicates that 100 percent whey protein is composed solely of a protein derived from milk. Whey is the liquid that remains after milk is turned into cheese. If the protein contained in whey is isolated from the other components, it is called whey protein. Purified whey protein is usually a dry powder.