Mis-firing refers to the situation where an engine or firearm fails to ignite properly. The antonyms for mis-firing are firing correctly, igniting smoothly, running smoothly, and functioning correctly. Efficiently operating, firing precisely, or working adequately can also be considered antonyms for mis-firing. In the context of the workplace or personal goals, antonyms could include excelling, achieving successfully, performing well, and making progress. When discussing interpersonal relationships, antonyms might include communicating effectively, resolving conflicts, engaging positively, and understanding one another. Overall, the opposite of mis-firing is success, effectiveness, or efficient operation.