weight gainer

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun bodybuilding : A high-calorie beverage or powdered drink used to bulk up the physique, especially the muscles. Typically, such beverages are very high in sugar content, and require drinking large volumes of the beverage.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a person who gains weight