The term 'Gallbladder Fluid' refers to the BILE produced by the gallbladder, which is a small organ located in the upper right side of the abdomen. BILE is a yellow-green fluid that helps to break down fats and absorb nutrients from food. It is composed of water, electrolytes, BILE acids, cholesterol, and bilirubin. BILE is secreted into the small intestine, where it aids in digestion. The four-letter word for this fluid is 'BILE'.