Kissing ass is a phrase used to describe someone who is excessively flattering or fawning over someone in a position of power. This term is often seen as crass or vulgar, and can be substituted with more appropriate synonyms. One such synonym is "brown-nosing," which refers to ingratiating oneself with someone through flattery or excessive compliments. Others include "sucking up," "buttering up," and "flattering." It's important to remember, however, that genuine compliments and showing appreciation for someone's efforts or achievements is not the same as kissing ass. It's important to strike a balance between showing respect and being genuine in interactions with others.