1. To fall or topple to some lower location or level. I feared the worst when I saw my grandfather tumble to the floor. He kicked the crate and watched it tumble to the basement.

2. obsolescent To arrive at some conclusion or understanding. I have since tumbled to the belief that animals prove far better companions than other people. It was only after the debt collectors began taking away our belongings that I tumbled to the reality of David's financial woes.