From Longman Dictionary of Contemporary Englishshadow economyˌshadow eˈconomy noun [countable] technical business activities that are difficult for the authorities to find out about, for example because they are illegal
Examples from the Corpus
shadow economy• The fact that the shadow economy is coming into the spotlight of open publicity is encouraging.From Longman Business Dictionaryshadow economyˈshadow eˌconomy [countable]ECONOMICS business activities that are difficult for the authorities to find out about, for example because they are against the lawSYNSHADOW MARKETThe official sector is losing its appeal as many Russians can make more money by working in the shadow economy. → economy 