Plural of charley, slang for a leg cramp or a British police officer, depending on context.
From the given name Charlie, used as a euphemism in British slang. The 'charley horse' (leg cramp) origin is disputed but became common in the 19th century. The police meaning comes from rhyming slang 'Charlie Ronce.'
The term 'charley horse' for leg cramps might come from a lame horse named Charley who belonged to a baseball pitcher in the 1880s—though that's one of several competing origin stories that nobody can definitively prove!
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