The original Latin usage of the word is a complete 180-degree turn from today. It meant "exceptionally good" and was used to let the best of the best shine. Through history, people began to use it ironically, labeling things egregious in a sarcastic tone and shifting the true meaning with every generation. Today, only the sarcastic meaning of the word has survived.
A more current shift that we've seen in a word is "literally," meaning exact. However, because people have used it informally to mean the exact opposite (for example: I've literally worked a million hours this week), the dictionary is starting to budge and allow it to have both meanings.
