Self-righteous is a term used to describe people who believe that their behavior is morally or ethically superior to others. Other synonyms for self-righteous include smug, holier-than-thou, sanctimonious, superior, and arrogant. These words describe individuals who believe that they are better than others based on their beliefs, actions, or attitudes. Additionally, the terms pompous and pretentious can also be used to describe self-righteousness since people who possess these traits believe that they are above others. In conclusion, whether you use self-righteous, smug, or sanctimonious to describe someone, the meaning remains the same- a sense of moral superiority.