The phrase "ill manners" can be replaced with a number of synonymous terms. One such term is "bad behavior," which can refer to a wide range of rude or inappropriate actions. Another option is "impolite conduct," which implies a lack of consideration or respect for others. "Discourtesy" and "rudeness" are also commonly used phrases that convey a similar meaning to ill manners. Finally, "incivility" is another word that can be used to describe a lack of respect or good manners, particularly in social situations. Regardless of the specific term used, all of these words convey a negative connotation and suggest a problem with social etiquette.