"Frederick North" was the name of a British prime minister who served during the American Revolution. As a historical figure, the name has few synonyms. However, the individual name components of "Frederick" and "North" can each translate to multiple synonyms. For instance, "Frederick" can be replaced with "Fred," "Fritz," or "Fedrick," among others. As for "North," one might consider using "Northerly," "Arctic," or "Northernmost" as synonyms. However, in the context of discussing the British prime minister himself, using his full name is likely the most appropriate option.