define arboretum
arboretumnoun [ C ] /ËÉË.bÉrËiË.tÉm/ /ËÉËr-/ plural arboretums or or arboreta. âº a large garden where many types of tree are grown, for people to look at and to be studied for scientific purposes. (Definition of âarboretumâ from the Cambridge Advanced Learner's Dictionary & Thesaurus Â© Cambridge University Press) Browse.