What does the abbreviation PO stand for? Meaning: by mouth; orally., A purchase order (PO) is an official document that is sent from a buyer to a seller, documenting the agreement for a sale of specific products and/or services. AP & AR Overview, 102 definitions of PO. Meaning of PO. What does PO stand for? PO abbreviation. Define PO at AcronymFinder.com., This page illustrates how PO is used in messaging and chat forums, in addition to social networking software like VK, Instagram, Whatsapp, and Snapchat. From the table above, you can view all meanings of PO: some are educational terms, the other are medical terms, and even computer terms., Looking for the definition of PO? Find out what is the full meaning of PO on Abbreviations.com! 'Post Office' is one option -- get in to view more @ The Web's largest and most authoritative acronyms and abbreviations resource., 8 meanings: British → an informal word for chamberpot polonium a river in N Italy, rising in the Cottian Alps and flowing. Click for more definitions..