partisan

(noun) a fervent and even militant proponent of something. Synonyms: zealot, drumbeater.

(noun) an ardent and enthusiastic supporter of some person or activity. Synonyms: enthusiast, partizan.

(noun) a pike with a long tapering double-edged blade with lateral projections; 16th and 17th centuries. Synonyms: partizan.

(adj) devoted to a cause or party. Synonyms: partisan (vs. nonpartisan), partizan.