Fire-eating is a term that is used to describe someone who is very passionate or aggressive in their beliefs or actions. There are several other words that can be used as synonyms for this term, including fervent, zealous, ardent, enthusiastic, militant, combative, and extremist. These words all convey the idea of someone who has strong convictions and is willing to act on them, whether that means taking a confrontational stance or pushing for change in a more subtle way. Regardless of the specific word used, all of these synonyms suggest a person who is not afraid to stand up for what they believe in and who is willing to take risks to achieve their goals.