"Boot-licker" is a derogatory term used to describe someone who excessively flatters or obeys someone in a position of power. It is an insulting term that implies subservience and lack of self-respect. There are several synonyms for this term, including brown-noser, sycophant, toady, ass-kisser, flatterer, yes-man, lapdog, lackey, and groveler. These words all describe someone who is willing to do whatever it takes to please their superiors, regardless of their personal beliefs or morals. While these traits may be desirable in certain contexts, being called a boot-licker is generally considered an insult and can be hurtful to those targeted by the term.