The phrase "more extensive" can be replaced by various synonyms depending on the context. For example, "wider," "broader," and "larger" can be used to describe physical size or area. When referring to comprehensive knowledge or understanding of a subject, "in-depth," "detailed," or "thorough" can be used instead. Similarly, "elaborate," "expansive," and "comprehensive" can be used to describe detailed plans or designs. In the realm of language, "profuse," "copious," and "abundant" may be used to express a great amount of writing or speaking. Overall, there are many synonyms for "more extensive," and the most appropriate choice will depend on the context in which the word is used.