What an Idiom!

Does the word "idiom" have anything to do with the word "idiot"?

I guess it does if we take a giant step back in time. The prefix "idio" comes from Greek, meaning personal, private, distinct. In English, idiom refers to several things—1. the language spoken in a particular area, 2. an expression or phrase that has meaning only in that language ("you can't pull the wool over my eyes"), 3. a manner of expression that's peculiar to an individual. According to the Oxford Dictionary of Word Histories, English borrowed the word idiom from French, which took it from Latin, which took it from Greek. Before Greek? I don't know.

Idiot, on the other hand is from Middle English and referred to an ignorant person or a lowbrow, and it's had a long and successful run in Modern English as well. But, ME can't claim to have coined the word, for it came from Latin, which borrowed it from Greek.

So, although the two words have the same parents, they weren't conjoined at birth, and they seem to have taken very different roads in their etymological lives. After all, there's a major difference between "an idiomatic expression" and "an idiotic expression."