knotweedPronunciation: /ˈnɒtwiːd/Definition of knotweed noun [mass noun] a plant of the dock family, which typically has sheaths where the leaves join the stems and is often an invasive weed. Polygonum and other genera, family Polygonaceae: several species, in particular Japanese knotweed knotgrass. knotweed in other Oxford dictionaries Definition of knotweed in the US English dictionary
