The phrase "for ages" is commonly used to describe a prolonged period of time. However, there are several synonyms that can be used instead of "for ages" to diversify your expressive vocabulary. One option is "for a long time," which has a similar meaning but offers a more concise way to express it. Another alternative is "for centuries," which is particularly useful when describing a period of time that spans multiple generations. Additionally, "for eons" can be used to describe an incredibly long period of time that seems almost infinite. Using these synonyms for "for ages" can help to make your writing or speech more interesting and engaging while still conveying the same idea.