To waddle means to walk with short steps while swaying from side to side, the way ducks and penguins move. Picture a duck crossing a pond's edge: its body rocks left and right with each step, creating that distinctive rolling walk. Penguins waddle even more dramatically because of their short legs and round bodies.

People waddle too, especially when something makes walking normally difficult. A toddler just learning to walk often waddles because they're still figuring out balance. Someone carrying a heavy backpack might waddle under the weight. If you've ever tried walking while holding something bulky between your knees, you probably waddled without meaning to.

The word captures both the movement and the slightly awkward, endearing quality of this walk. When someone says a character in a story “waddled across the room,” you can immediately picture that side-to-side motion. It's not an insult: waddling is just how certain animals naturally move, and how people move when circumstances make a normal stride difficult.