A lip server is someone who flatters and compliments others insincerely or excessively. Other synonyms for this term include a flatterer, sycophant, toady, apple-polisher, brown-noser or suck-up. These individuals will often use empty flattery and false praise to try to gain favor with others or advance their own agenda. However, their insincerity and manipulative behavior often backfire, and they can quickly lose the trust and respect of those around them. It's best to avoid becoming a lip server and instead strive to build genuine relationships based on honesty, integrity, and mutual respect.