Autonomist refers to a person who advocates for self-government or independence, which makes it difficult to find perfect synonyms. However, some words closely related to autonomist may include separatist, nationalist, self-determinist, self-ruling, and libertarian. These words all describe someone who seeks to gain more control over their own affairs, whether in politics, economics, or other spheres of life. While the specific meanings of these terms may vary slightly, they all indicate a desire for greater autonomy and independence. In short, synonyms for autonomist highlight the desire for self-rule and independence from outside influence.