Definition of "ethical"

(philosophy, not comparable) Of or relating to the study of ethics.  examples

(not comparable) Of or relating to the accepted principles of right and wrong, especially those of some organization or profession.  examples

(comparable) Morally approvable; good.  examples

(of a drug, not comparable) Only dispensed on the prescription of a physician.  examples

An ethical drug, one only dispensed on the prescription of a physician.  examples