Yours, Etc.: Origins and Uses of 8 Sign-Offs
c.1600, "pertaining to morality," from ethic + -al (1). Related: Ethicality; ethically.
ethical eth·i·cal (ěth'ĭ-kəl)adj.
Of, relating to, or dealing with ethics.
Being in accordance with the accepted principles of right and wrong that govern the conduct of a profession.