What is the prefix for apology?

There isn't a specific prefix for "apology". However, there are prefixes that can be used to create related words, like:

* Apolog - This is the root word, and you can add prefixes like un- to create "unapologetic".

* Excus - You could add prefixes like re- to create "excuse" and dis- to create "disexcuse" (though this is less common).

It's important to remember that "apology" itself is already a complete word, so a direct prefix is not needed.