A bud is a small bump on a plant stem that will eventually open and become a flower, leaf, or new branch. In early spring, you might notice tiny buds appearing on bare tree branches, each one tightly wrapped and waiting for warmer weather. Inside each bud, new growth sits folded and protected, ready to unfold when conditions are right. Rose buds are especially beautiful, with their petals curled up inside green protective leaves called sepals.

The word also describes something in its early stages. When scientists say an idea is still budding, they mean it's just beginning to develop. A budding pianist is someone whose talent is starting to show. The phrase “nip it in the bud” means to stop something problematic before it can grow larger, like a gardener might pinch off unwanted buds.

People also use bud as a casual, friendly way to address someone, like “hey, bud” or “thanks, bud.” It suggests the warmth of friendship without being overly formal. You might call your younger brother bud, or a coach might call players bud to show he cares about them.