"Kiss ass" is often used as a derogatory term to describe someone who flatters and sucks up to others in order to gain favor or advantage. In a professional setting, this behavior is often seen as insincere and manipulative.
There are a number of synonyms for "kiss ass" that range from mild to more offensive. Some examples include brown-noser, bootlicker, flatterer, sycophant, toady, yes-man, and apple-polisher. These terms are often used to criticize individuals who are seen as lacking integrity and honesty in their interactions with others.
In contrast, positive synonyms for "kiss ass" include supportive, encouraging, and empathetic. These terms highlight the importance of building relationships through genuine connection and understanding, rather than shallow flattery and manipulation.