The phrase "advance an idea" is a way to communicate the act of promoting or proposing an idea to someone else. There are various synonyms that can be used to describe this action, such as proposing, suggesting, advocating, pitching or presenting an idea. Each of these words expresses a slightly different connotation, but all aim to convey the idea of putting forward an idea to gain support or consideration from others. It is important to choose the right synonym in the given context to ensure clear and effective communication. Thus, depending on the situation, one may choose to substitute "advance an idea" with any of the synonyms mentioned above.