You ramble when your talking or your walking goes on and on and on. And on. You’re in no hurry to make a point or get to your destination — if there is one at all.
The word ramble comes from similar roots as roam. They both mean wander, but they’re often used a little differently. You might roam around on vacation to relax or find adventure. If you’re a shark, you roam the deep sea for food. On the other hand, if the person on the plane next to you chatters nervously and can’t stop, you wish they wouldn’t ramble on like that.