rue

(noun) European strong-scented perennial herb with grey-green bitter-tasting leaves; an irritant similar to poison ivy. Synonyms: herb of grace, Ruta graveolens.

(noun) leaves sometimes used for flavoring fruit or claret cup but should be used with great caution: can cause irritation like poison ivy.

(noun) sadness associated with some wrong done or some disappointment. Synonyms: sorrow, regret, ruefulness. Examples: "He drank to drown his sorrows." "He wrote a note expressing his regret." "To his rue, the error cost him the game."

(noun) (French) a street or road in France.

(verb) feel remorse for; feel sorry for; be contrite about. Synonyms: repent, regret.