Ass-kissing, also known as brown-nosing or sucking up, refers to the act of excessively flattery or praising someone with the intention of gaining favour or benefits. Other synonyms for ass-kissing include bootlicking, grovelling, toadying, flattering, fawning, obsequiousness, sycophancy, and ingratiating. These terms are commonly used to describe individuals who are willing to go to any length to please their superiors or those in positions of power. While flattery may be appreciated by some, it can often be seen as insincere or manipulative. It is important to maintain a balance between showing respect and indulging in excessive flattery in professional and personal relationships.