do ill 0 synonyms found No synonyms found for do ill. Try a different form of the word. Definition (n) : an herb (Peucedanum graveolens), the seeds of which are moderately warming, pungent, and aromatic, and were formerly used as a soothing medicine for children; -- called also dillseed; a cucumber pickled with dill flavoring (v) : to still; to assuage; to calm; to soothe, as one in pain; to lull to sleep