Noun
1. European strong-scented perennial herb with gray-green bitter-tasting leaves; an irritant similar to poison ivy
2. leaves sometimes used for flavoring fruit or claret cup but should be used with great caution: can cause irritation like poison ivy
3. sadness associated with some wrong done or some disappointment;
"he drank to drown his sorrows""he wrote a note expressing his regret""to his rue, the error cost him the game"4. (French) a street or road in France