Long-lived means lasting for a long time or living for many years. A long-lived species, like the giant tortoise, can survive for over a century. A long-lived tradition, like celebrating Thanksgiving, continues generation after generation.

The word applies to living things and ideas alike. Redwood trees are long-lived, some reaching over 2,000 years old. The U.S. Constitution has proven remarkably long-lived, guiding the nation for more than two centuries. A long-lived friendship between two people endures through moves, changes, and the passage of time.

Scientists study what makes certain creatures long-lived. Bowhead whales can live over 200 years, while some bristlecone pines in California have stood for nearly 5,000 years. Understanding why these organisms are long-lived helps researchers learn about aging itself.

The opposite is short-lived: mayflies exist as adults for just a single day, and some trends or fads disappear almost as quickly as they arrive. When something proves long-lived, it often has qualities that help it last, such as strength, usefulness, or deep roots that weather storms and seasons.