The term "wise guy" is often used to describe someone who is overly confident or arrogant, and thinks they know everything. However, there are a number of synonyms that can be used to describe this type of person. One common term is "know-it-all," which implies that the person believes they have all the answers and are always right. Another option is "smart aleck," which suggests that the person is not only confident but also somewhat annoying or disrespectful. Other possible synonyms might include "smarty pants," "wiseacre," or "wiseass." No matter which term you choose, it's clear that these individuals can be difficult to deal with and are not always appreciated by those around them.