From Longman Dictionary of Contemporary Englishsleeping partnerˌsleeping ˈpartner noun [countable] British English BBsomeone who owns part of a business but is not actively involved in running it SYN silent partner American English
Examples from the Corpus
sleeping partner• He retired formally from Harland & Wolff in 1906, although effectively he had been a sleeping partner for over ten years.• It is possible that Storr continued the concern, Fogelberg perhaps acting as the sleeping partner.• It stood at stud at Craigie and half of its earnings were paid to William Dunlop, the sleeping partner.From Longman Business Dictionarysleeping partnerˌsleeping ˈpartner British English (also silent partner)COMMERCE a partner who invests in a business but does not take an active part in managing it → partner 