eth·i·cal[ˈeTHək(ə)l]ADJECTIVE relating to moral principles or the branch of knowledge dealing with these."ethical issues in nursing" · [more]synonyms: moral · social · behavioral · having to do with right and wrongmorally good or correct."can a profitable business be ethical?"synonyms: morally correct · right-minded · right-thinking · principled · [more]avoiding activities or organizations that do harm to people or the environment."an expert on ethical investment" · [more](of a medicine) legally available only on a doctor's prescription and usually not advertised to the general public.