Append/əˈpend/ Definition 1 of 3Pro Tip 1/3Supplementary Use Use 'append' to indicate adding extra information that is not essential but helpful. You can append your contact information at the bottom. Pro Tip 2/3Conclusive Addition 'Append' implies something is being added at the end after the main part is complete. She wrote her thesis and appended her references. Pro Tip 3/3Postscript Context Commonly used when adding a P.S. in personal letters to add an afterthought. P.S. I appended a small gift for you.