Glad-handing is a colloquial term that refers to overly friendly behavior that is meant to further one's personal or professional interests. It can also be seen as insincere and manipulative. Some synonyms for glad-handing include ingratiating, fawning, obsequious, sycophantic, and toady. Other words that can be used to describe someone who engages in glad-handing activities include flatterer, bootlicker, yes-man, and brown-noser. These words are often used when referring to people who excessively praise or flatter others in order to gain favor, connections, or promotions. While glad-handing can be a useful tool in certain situations, it can also seem dishonest and untrustworthy.