limb

The word "limb" has two main everyday uses. Most often, it means an arm or a leg, especially when speaking in a general, medical, or slightly formal way. In medical language, people may talk about the "upper limbs" and "lower limbs." An athlete may train their limbs to improve speed and strength, and a doctor may examine an injured limb after a fall. The word can also be used for the similar body parts of animals.

In the world of trees, a "limb" is a large branch growing from the trunk or from a main branch. These strong branches help form the shape of the tree and hold up smaller branches, leaves, flowers, and fruit. Think of a willow tree with long limbs bending toward the water, or a big apple tree whose heavy limbs carry fruit in late summer.

Beyond these common meanings, "limb" can sometimes describe a part that reaches out from a larger whole, though this use is much less common today. You are more likely to meet the word in the idiom "go out on a limb," which means to take a risk, speak boldly, or support something when you are not fully safe or certain. The image is easy to feel: someone moving onto a thin branch where there is little support.

The word comes from the Old English lim, meaning a part or member of a whole. That old idea still lives inside the modern word. Whether you are talking about a child waving a tired arm, a dog injuring a front leg, or a tree stretching its branches into the sky, "limb" suggests a part that extends outward and plays an important role in the whole.