There are various synonyms for the term "extra pages." One of them is "supplementary sheets," which can be used to refer to additional pages added to a document or book. Another synonym is "appendix," which is a section at the end of a book or document that contains additional information or data that is not included in the main text. "Annexes" can also be used interchangeably with "extra pages," as they are used to indicate an attachment or an extension of the main document or book. Moreover, "addenda" and "additions" are synonyms that refer to additional pages that are included after the completion of the main manuscript.