If asked to pick the most complex word in the English language, what comes to mind? Maybe something long and intricate like “antidisestablishmentarianism” or “honorificabilitudinitatibus.” Maybe it’s a medical word, or one with silent letters like “pneumonia.”

Chances are you wouldn’t automatically pick out a three-letter word that you use in everyday conversation. But that’s just it — the richest word in English is “run.”

Why does this one little word hold so much weight? According to Simon Winchester, who wrote The Professor and the Madman: A Tale of Murder, Insanity and the Making of the Oxford English Dictionary and is an expert on the subject, it’s because there are 645 meanings of its verb form alone.

The word that used to hold such an impressive standing was “set,” which took up 32 full pages of the original Oxford English Dictionary, proving that smaller certainly does not mean less intricate. So why did “run” overrun “set,” and the next champion, “put”?

“It is a feature of our more sort of energetic and frantic times that set and put seem, in a peculiar way, sort of rather stodgy, rather conservative, whereas run, not least all the meanings that have come from the Industrial Revolution — machines run, clocks run, computers run — there are all of those which began in the middle of the 19th century,” Winchester told NPR.

The next edition of the Oxford English Dictionary, with every definition of “run” included, is set to go to print in 2037. Until then, you can let all of the hundreds of definitions run through your head.

Watch this

What to Know for the Upcoming Flu Season