Rue

1. noun

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

2. noun

   European strong-scented perennial herb with grey-green bitter-tasting leaves; an irritant similar to poison ivy

   Similar: herb of grace, ruta graveolens

3. noun

   sadness associated with some wrong done or some disappointment

   “he drank to drown his sorrows”

   Similar: sorrow, regret, ruefulness

4. verb

   feel remorse for; feel sorry for; be contrite about

   Similar: repent, regret