rue2Pronunciation: /ruː/Translate rue | into Italian | into Spanish Definition of rue noun a perennial evergreen shrub with bitter strong-scented lobed leaves which are used in herbal medicine. Ruta graveolens, family Rutaceae used in names of other plants that resemble rue, especially in leaf shape, e.g. goat’s rue, meadow rue, and wall rue. Origin: Middle English: from Old French, via Latin from Greek rhutērue in other Oxford dictionaries Definition of rue in the US English dictionary