The word "most second-fiddle" can mean someone or something that is not the primary focus or is in a subordinate position. Antonyms for this term could include: primary, principal, leading, superior, top-notch, elite, prominent, and noteworthy. These words describe someone or something that is at the forefront or in the most important position. By contrast, the word "most second-fiddle" could also be replaced with synonyms such as secondary, subordinate, or lesser to emphasize the position or importance of an alternative person or thing. Ultimately, the use of the word "most second-fiddle" will depend on the context of the situation and the intent behind the language used.