cranberry tree \cranberry tree\, cranberry-tree \cranberry-tree\n. a deciduous thicket-forming Old World shrub ({Viburnum opulus}) with clusters of white flowers and small bright red berries. It is sometimes called {high cranberry} to distinguish it from the {marsh cranberry} or {low cranberry}. Syn: guelder rose, European cranberrybush, European cranberry bush, crampbark, {Viburnum opulus}. [WordNet 1.5]