A zealous advocate is someone who is passionate and enthusiastic about advocating for a particular cause, person or belief. Some synonyms for a zealous advocate include "passionate supporter," "ardent champion," "tireless campaigner" and "committed crusader." Other possible synonyms include "staunch defender," "fervent advocate," "dedicated ally," and "vigorous supporter." A zealous advocate is someone who will go above and beyond to promote and defend their cause or beliefs with an unwavering determination and passion. Regardless of the synonym used, a zealous advocate is someone who is deeply committed to their cause and will stop at nothing to ensure that their voice is heard.