Ass-licking is a vulgar term that refers to insincere or excessive flattery. However, there are several alternative words and phrases that can be used to convey a similar meaning. Some common synonyms for ass-licking include brown-nosing, sucking up, buttering up, and kissing up. These terms all imply a sense of dishonesty and insincerity in a person's behavior. Other synonyms include toadyism, fawning, and obsequiousness, which all suggest that someone is behaving in a subservient or servile way in order to gain favor or approval. While these words may carry negative connotations, they accurately describe a type of behavior that is often viewed as manipulative or untrustworthy.