1. (Science: botany) A perennial suffrutescent plant (Ruta graveolens), having a strong, heavy odour and a bitter taste; herb of grace. It is used in medicine.
Then purged with euphrasy and rue The visual nerve, for he had much to see. (milton) They exorcists are to try the devil by holy water, incense, sulphur, rue, which from thence, as we suppose, came to be called herb of grace. (Jer. Taylor)
2. Bitterness; disappointment; grief; regret. Goat’s rue. See goat. Rue anemone, a pretty springtime flower (Thalictrum anemonides) common in the united states. Wall rue, a little fern (Asplenium Ruta-muraria) common on walls in Europe.
Origin: F. Rue, L. Ruta, akin to Gr.; cf. AS. Rde.