A group of mostly rich countries that work together on money, jobs, trade, and growth. It is a club for talking, sharing numbers, and suggesting rules — not a country, not a bank, and not a court. News reports often use OECD figures to say how well a country is doing compared with other rich ones. People say the letters as a name, “O-E-C-D,” almost never the long title. Taiwan is not a member. It is also not the United Nations and not the European Union, though students sometimes pile all the big letter-groups into one heap.