Flub-up, which means to mess up or make an error, has several antonyms that convey the opposite meaning. One antonym for flub-up is succeed, which means to accomplish a goal or task effectively. Another antonym is nail, which refers to achieving an objective or performing a task perfectly. Conversely, flub-up has a synonym called a blunder, and its antonym is a success. To avoid flubbing-up in a particular area, one must show proficiency, which is the opposite of incompetence, or adeptness, which refers to being skilled or expert in an area. In short, the antonyms for flub-up represent desirable outcomes, such as success, mastery, and efficiency.