The phrase "on the improve" means that something is getting better or improving. There are several synonyms that can be used in place of on the improve, such as getting better, progressing, developing, advancing, evolving, growing, and thriving. All of these words suggest a positive change or trend in a particular situation or circumstance. Other synonyms for on the improve may include improving, ameliorating, correcting, enhancing, and upgrading. These words are often used in relation to personal or professional development, as well as in the context of business or economic growth. Overall, the use of synonyms can help to add variety and depth to language, while conveying a similar meaning.