Brownnosing is a term that is commonly used to refer to someone who tries to gain favor with someone else by flattery or excessive praise. However, there are several other synonyms that can be used to describe this behavior as well. One of these is "apple polishing," which refers to a similar behavior where someone tries to gain favor by showing excessive respect or admiration. Another synonym is "bootlicking," which refers to someone who is excessively accommodating or fawning towards someone else, often in an attempt to gain their favor or approval. Ultimately, all of these terms refer to the same type of behavior, and can be used interchangeably depending on the context.