The term "most underneath" refers to the most hidden, concealed or covert aspect of something, often its root or underlying cause. Some antonyms might include "most visible," "most apparent," or "most overt." Other antonyms might include "most superficial," "most exterior," or "most superficial." These terms indicate that the most prominent or easily visible aspect of something is being referred to, as opposed to its inner workings or underlying factors. Thus, antonyms for "most underneath" can help to clarify meaning and provide readers with a more complete understanding of a given concept or idea.