"The glad hand" is a phrase that refers to someone who appears friendly and enthusiastic on the surface but is insincere in reality. There are several synonyms for this phrase, such as "smarmy," "unctuous," "sycophantic," "obsequious," and "fawning." Each of these synonyms describes someone who is excessively eager to please others and gain favor but lacks genuine sincerity and honesty. These qualities can be perceived as manipulative and disingenuous, making people wary of individuals who exhibit them. Whether in a business or personal setting, it's important to be aware of these characteristics to avoid falling prey to those using "the glad hand".