Glad-handering, which means to excessively flatter or be overly friendly for personal gain, has several antonyms. To start with, one could use the phrase 'honesty and transparency' to signify the opposite of glad-handering. Additionally, the use of frankness, sincerity, or straightforwardness can be employed to show a lack of insincerity. Authenticity, integrity, and modesty are other possible antonyms to glad-handering, highlighting the importance of genuine behavior in social interactions. Lastly, bringing attention to competence, diligence, and professionalism is another excellent strategy for countering glad-handering. Overall, these antonyms emphasize the importance of honesty, authenticity, and genuine communications in building meaningful relationships.