Kissupping is a term used to describe someone who flatters or ingratiates themselves with another person, often for personal gain. There are several synonyms for this word, including brown-nosing, bootlicking, buttering up, sucking up, and groveling. Each of these words has a slightly different connotation, but all refer to the act of excessively flattering someone in order to gain favor or advance one's own interests. Regardless of the term used, kissupping is generally seen as insincere and manipulative behavior, and is not a desirable trait in any social or professional context.