Japanese knotweednoun [ U ]
uk/dʒæp.ənˌiːz ˈnɒt.wiːd//dʒæp.ənˌiːz ˈnɑːt.wiːd/a plant with hollow stems and wide leaves that grows extremely quickly and is difficult to control or destroy:
Japanese knotweed is known to be able to damage foundations, grow through patios and floors, and block drains.