Where did the word oxymoron come from?

The word "oxymoron" comes from the Ancient Greek phrase ὀξύμωρον (oxymōron), which itself is a combination of two Greek words:

* ὀξύς (oxús) meaning "sharp, pointed, keen"

* μωρός (mōrós) meaning "foolish, dull, stupid"

Therefore, literally translated, "oxymoron" means "sharp-dull". This combination of contrasting or contradictory terms is exactly what an oxymoron is!