When it comes to expressing a physical altercation or a heated verbal exchange, there are many synonyms for the phrase "duke it out". Some alternatives to this phrase include "throw down", "scrap", "brawl", "fight it out", "battle", "clash", and "tussle". Each of these phrases conveys a sense of confrontation and intensity, whether it be a physical fight or a verbal argument. Depending on the context and tone of the situation, different synonyms may be more appropriate than others. However, each of these phrases encapsulates the idea of a contest or struggle between two opposing forces.