Antonyms for the phrase "marks out" include phrases such as "misses the mark", "loses sight of", and "falls short of". These opposing terms describe the failure to accurately identify or achieve a target, goal or objective. While "marks out" implies success in mapping out or setting a clear path, the antonyms suggest a lack of direction and failure to meet expectations. It's important to note that antonyms are often used to highlight the opposite qualities of a particular word or phrase, and in this case, they underscore the importance of precision and focus in achieving success.