1. A supplementary document attached to the end of a writing (the brief includes an appendix of exhibits). • For the requirements of an appendix to a federal appellate brief, see Fed. R. App. P. 30.
2. English law. A volume that contains material documents and other evidence presented in a lower court. • The volume is used by the House of Lords or Privy Council when functioning as an appellate tribunal. Pl. appendixes, appendices.