The antonyms for the word "most compound" would be something simple, basic, or uncomplicated. Some other possible antonyms could include easy, straightforward, or plain. These words all have the opposite meaning of compound, which is complex or made up of multiple parts. In many cases, the opposite of "most compound" is something that is clear or easy to understand, such as a simple definition or straightforward explanation. While complex compounds can be useful in certain settings, there are also many cases where a more basic or simple approach is needed to achieve the desired result.