From Longman Dictionary of Contemporary EnglishR & DR & D /ˌɑːr ən ˈdiː/ noun [uncountable] BB (research and development) the part of a business concerned with studying new ideas and planning new productsFrom Longman Business DictionaryR and DR and D (also R&D) noun [uncountable]MANUFACTURING1research and development; the part of a business concerned with studying new ideas and planning new productsWe attempt to relate expenditure on R and D to performance.Dunlop’s R and D manager Bob Haines2research and development; the department in a company responsible for developing new products, improving existing products etcShe works in R and D.