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 is a natural part of milk, so you have to avoid all milk products. Unfortunately, whey is also an extremely popular food additive. Avoiding whey means understanding food-labeling terms, carefully reading labels and asking a lot of questions.