Putting on airs is a phrase used to describe someone who is behaving in an arrogant manner or pretending to be more sophisticated than they really are. There are several synonyms that can be used to substitute this phrase, including acting haughty, being pretentious, showing off, acting superior, or being pompous. These synonyms highlight the insincerity and lack of authenticity inherent in this kind of behavior. Ultimately, putting on airs is nothing more than a superficial attempt to impress others, but in reality, it often results in negative perceptions and can even be detrimental to one's personal or professional relationships.