Cusser is a derogatory term used to describe someone who is either vulgar, abusive, or profane. There are a plethora of synonyms that can be used to describe someone who exhibits such behavior. Some common alternatives include swearer, curser, potty-mouth, foulmouth, vulgarian, and expletive enthusiast. Other options include rude person, impolite speaker, bad-mannered individual, or simply, someone who lacks civility. While these terms may vary in intensity and usage, they all essentially illustrate the same type of person who has a penchant for using offensive language that is not acceptable in polite society.