What is Loyalty?

Legal Definition
Loyalty is devotion and faithfulness to a cause, country, group, or person. Philosophers disagree on what can be an object of loyalty as some argue that loyalty is strictly interpersonal and only another human being can be the object of loyalty.

John Kleinig, professor of philosophy at City University of New York, observes that over the years the idea has been treated by writers from Aeschylus through John Galsworthy to Joseph Conrad, by psychologists, psychiatrists, sociologists, scholars of religion, political economists, scholars of business and marketing, and—most particularly—by political theorists, who deal with it in terms of loyalty oaths and patriotism. As a philosophical concept, loyalty was largely untreated by philosophers until the work of Josiah Royce, the "grand exception" in Kleinig's words. John Ladd, professor of philosophy at Brown University, writing in the Macmillan Encyclopedia of Philosophy in 1967, observes that by that time the subject had received "scant attention in philosophical literature". This he attributed to "odious" associations that the subject had with nationalism, including Nazism, and with the metaphysics of idealism, which he characterized as "obsolete". However, he argued that such associations were faulty and that the notion of loyalty is "an essential ingredient in any civilized and humane system of morals". Kleinig observes that from the 1980s onwards, the subject gained attention, with philosophers variously relating it to professional ethics, whistleblowing, friendship, and virtue theory.
-- Wikipedia
Legal Definition
That which adheres to the law, that which sustains an existing government. See Penal Laws of China, 3.
-- Bouviers Law Dictionary
Legal Definition
Adherence to law. Faithfulness to one's prince or sovereign or to the existing government.
-- Black's Law Dictionary
Legal Definition
Devotion to the government or to law.
-- Ballentine's Law Dictionary