Oxford Dictionary English postal order nounnoun BrE BrE//ˈpəʊstl ɔːdə(r)// ; NAmE NAmE//ˈpoʊstl ɔːrdər// (British English) (also money order North American English, British English) (abbreviation PO) Add to my wordlistjump to other resultsan official document that you can buy at a bank or a post office and send to somebody so that they can exchange it for moneyCheck pronunciation: postal order oxfordlearnersdictionaries.com