There are many synonyms for the phrase "largest fortune" that can be used to describe the massive wealth of individuals and businesses. Some of the most common synonyms include "biggest wealth," "greatest riches," "massive prosperity," "enormous affluence," "huge abundance," and "immense opulence." Additionally, some other words that can be used in place of "large" or "biggest" include "grand," "tremendous," "colossal," "towering," and "monumental." Regardless of the specific words used to describe a person's or company's wealth, the implication is always one of immense abundance and prosperity, with the ability to influence and change the world on a grand scale.