The word "most perseverant" implies a high level of dedication and determination towards a particular goal or task. Antonyms for this word could include "least persistent," "unmotivated," or "quitter." These words suggest a lack of the drive or desire to stick to a task or goal, and may indicate a tendency to give up easily. Other antonyms include "inconsistent," "fickle," or "easily distracted," implying a lack of focus and commitment. It is important to note that these antonyms do not necessarily suggest a negative character trait, but rather indicate a contrast in behavior and attitude towards achieving goals.