post·al or·der
noun/ˈpəʊstl ɔːdə(r)/
/ˈpəʊstl ɔːrdər/
(British English) (also money order North American English, British English)
(abbreviation PO)
- an official document that you can buy at a bank or a post office and send to somebody so that they can exchange it for money
（银行或邮政）汇票