The use of profanity or vulgar language is often seen as inappropriate or offensive in many social situations. Instead of using the phrase 'use bad language', there are several synonyms that can be used to describe this behavior. One common phrase is 'swear words', which refers to offensive or vulgar language used to express emotion or frustration. Other synonyms include 'curse words', 'cussing', 'blasphemy', 'expletives', or 'foul language'. These words may be used to describe the use of profanity in a casual or formal setting, or to denounce the use of language that is considered to be disrespectful or unacceptable.