Which English word has the most definitions?

Which word has the most definitions in the English language? Here's a hint: the word is only three letters long, can be a noun or a verb, and has more than 600 senses (or meanings), according to the Oxford English Dictionary via Mental Floss.

Apparently, the most meaning-full word used to be "set," which boasts over 400 senses. But that word was "set" back to runner-up after "advancements in technology" helped boost the amount of definitions for the new winning word, which is now "run."

From Mental Floss:

As a verb, [run] boasts a record-setting 645 definitions. Peter Gilliver, a lexicographer and associate editor of the Oxford English Dictionary, spent nine months sussing out its many shades of meaning.

This wasn't always the case, though. When the first edition of the Oxford English Dictionary was published in 1928, the word with the most definitions was set. However, the word put later outpaced it, and run eventually overtook them both as the English language's most complex word. Winchester posited that this evolution is partly due to advancements in technology (for instance, "a train runs on tracks" and "an iPad runs apps").

As for the longest word in the dictionary? Here's a hint to help: it's 45 letters long and means a lung disease "caused by inhalation of very fine silicate or quartz dust," according to Merriam-Webster. Yep, you got it: pneumonoultramicroscopicsilicovolcanoconiosis.

Previously: Redditor's share they're list of most annoying grammatical error's