Other forms: longer-lived; longest-lived
Long-lived things have been around for a very long time. By the smell of your couch, you may want to describe it as long-lived.
You can describe people who live to be quite old as long-lived: "All the men in my family are remarkably long-lived." It's also a good word for talking about inanimate objects that keep working for a long time, or even ideas that stick around: "His childhood plan to join the circus turned out to be long-lived — it was still his dream at the age of 35."