From Longman Business Dictionarymercantile exchangeˈmercantile exˌchange [countable]FINANCE a place where people meet to buy and sell things, often COMMODITIES (=oil, metals, farm products etc)the Chicago Mercantile Exchange → exchangemercantile exchangeˌmercantile exˈchange noun [countable]COMMERCE a place where people meet to buy and sell things, often COMMODITIES (=oil, metals, farm products etc)the Chicago Mercantile Exchange