The term "most right on" is a colloquialism used to describe something that is correct or accurate. Antonyms, or words with opposite meaning to "most right on," could include inaccurate, incorrect, wrong, false, or erroneous. These words can be used to indicate that something is not facts or true, and is instead based on misunderstanding, misinformation, or ignorance. It is important to note that antonyms are contextual and may not always be suitable replacements for the original word. In situations where precision is important, it is recommended to use appropriate alternatives that convey the intended meaning clearly and accurately.