When it comes to synonyms for the phrase "friend at court," many different options may come to mind. For example, "ally" could be used to describe someone who is a friend at court, as they are someone who is on your side and willing to support you. "Advocate" is another word that could be used in this context, as it implies someone who is willing to speak up on your behalf and fight for your rights. "Champion" is another possible synonym for friend at court, as it conveys the idea of someone who is willing to go to bat for you and be your advocate even in the face of adversity. Ultimately, the choice of synonym will depend on the specific context and the particular nuances that you want to capture.