Kissass is a derogatory term for a person who flatters or excessively praises someone to gain favor or advantage. There are many synonyms for this word, including brown-noser, suck-up, bootlicker, toady, sycophant, flatterer, praise-singer, apple-polisher, crawler, and groveler. These words indicate someone who is insincere and manipulative in their attempts to curry favor with another person. While it is important to show appreciation for others, doing so solely for the purpose of personal gain is considered disingenuous and untrustworthy. It is essential to be authentic and genuine in our relationships to build trust and respect with others.