botanical garden
From Longman Dictionary of Contemporary EnglishRelated topics: Outdoorbotanical gardenboˌtanical ˈgarden noun [countable] HBPDLOa large public garden where many different types of flowers and plants are grown for scientific studyExamples from the Corpusbotanical garden• Trees from every continent turn King's Park into a giant botanical garden.• Another neat toy: an on-line tour of botanical garden Web sites.• Founded in 1673, this small walled garden is the oldest botanical garden in the country after Oxford's.