If you look up online the etymology of the English word "general," you will be told that it derives from the Latin word "generalis." That is true as far as it goes.
Yet many Latin words are derived from Greek predecessors, as may be inferred from the fact that Wiktionary notes that "genikos" is an ancient Greek word that can easily be seen to connote the concept of a class or set, as in "genus" and "general."