One who goes to restauraunts, mainly fast food places, and orders water in place of any other drink to avoid paying higher costs overall. When done right, one can get more food for a price less than a combo on the combo menu by not getting a drink. For example, at Wendy's, you can get a burger and fries and a drink for about $4, but if you Water Loaf than you can get 2 Texas Double Cheeseburgers, a fry and chili with a water for the same price.
Today we went to Taco Bell and Brandon water loafed to get more food for his $5 than Kelley who didn't water loaf and got less for $5. Brandon will get more bang for his buck for being a Water Loafer.