The phrase "learned one" refers to a person who is knowledgeable or well-educated. There are many synonyms for this phrase, including scholar, pundit, sage, erudite, theologian, intellectual, expert, savant, and authority. Each of these words emphasizes a slightly different aspect of someone who is learned, such as their depth of knowledge, their particular area of expertise, or their position as a respected advisor or mentor. Whether you're describing a professor, a religious leader, or simply someone who loves to read and learn, these synonyms can help you capture the essence of someone who has great knowledge and wisdom.