From Longman Dictionary of Contemporary Englishbig businessˌbig ˈbusiness noun [uncountable] 1 BBvery large companies, considered as a powerful group with a lot of influence2 BBa product or type of activity that people spend a lot of money on Dieting has become big business.
Examples from the Corpus
big business• In its many forms, disposal of the dead has always been big business, and always subject to fashion.• Health and fitness now equal big business.• Ocean racing is big business involving vast amounts of money.• Selling music to teenagers is big business.• She asked the pastor, Will you lobby big business and the Legislature and get them to raise wages for women?• Conferences are now big business for Blackpool, and bring extra traffic in the early and late seasons.• The bureaucrats imposed rules and regulations on big business.• Indeed, if Democrats are to be believed, the entire Bush administration is in hock to big business.From Longman Business Dictionarybig businessˌbig ˈbusiness [uncountable]COMMERCE1very large companies considered as a powerful group with a lot of influenceReformers are trying to cut the links between government and big business.2a product or activity where a lot of money is involvedPet food is big business.Trafficking in stolen cars has become big business across eastern Europe. → business 