One Word with 645 meanings

What's the Most Complicated Word in English?

A three-letter-word with 645 meanings.

According to the editors of the Oxford English Dictionary, the most complicated word in the English language is something we're all familiar with. Believe it or not, the three-lettered word “run” yields as many as 645 different meanings and this is only for the verb. The most recent edition of the dictionary used 75 columns for this word alone. Behind these columns of description is nine months of relentless research and arduous compilation from one professional lexicographer, Peter Gilliver. Partly because of this word, the letter R section required more than nine months of harnessing so as to create a comprehensive list of meanings.