The phrase "militant tendency" refers to a strong and aggressive attitude or behavior. Some synonyms for "militant tendency" include belligerence, combative stance, bellicosity, pugnacity, aggressiveness, and hostility. These words indicate a willingness to engage in conflict or violence, often for ideological reasons. Other related synonyms include radicalism, extremism, and fanaticism, which suggest an intense commitment to a particular cause or belief system. However, it is important to remember that while these words can be used to describe individuals or groups with extreme viewpoints or aggressive behaviors, they do not necessarily imply any illegal or harmful actions.