A bulge is a rounded bump or swelling that sticks out from a normally flat or smooth surface. When you stuff too many books into your backpack, it creates bulges where the fabric stretches over the corners. When someone hides a cookie in their pocket, you might notice a telltale bulge giving away their secret snack.

The word describes something protruding outward in a rounded way, different from a sharp point or edge. A squirrel's cheeks bulge when stuffed with acorns. Your eyes might bulge in surprise when you see something shocking (though they don't actually pop out, they just open very wide). A wall might develop a bulge if water damage weakens it, or a tin can might bulge if the food inside has gone bad and created gas.

As a verb, to bulge means to swell outward: “His muscles bulged as he lifted the heavy box.” The word often suggests something is overfull or under pressure, like a suitcase bulging at the seams because you packed too much for vacation.