allegiance

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Loyalty or the obligation of loyalty, as to a nation, sovereign, or cause. synonym: fidelity.
• noun The obligations of a vassal to a lord.

from The Century Dictionary.

• noun The tie or obligation of a subject or citizen to his sovereign or government; the duty of fidelity to a king, government, or state.
• noun Hence Observance of obligation in general; fidelity to any person or thing; devotion.
• noun Synonyms Allegiance, Loyalty, Fealty. Allegiance is the most formal and official of these words; it is a matter of principle, and applies especially to conduct; the oath of allegiance covers conduct only.
• noun Loyalty is a matter of both principle and sentiment, conduct and feeling; it implies enthusiasm and devotion, and hence is most frequently chosen for figurative uses: as, loyalty to a lover, husband, family, clan, friends, old traditions, religion. Neither allegiance nor loyalty is confined to its original meaning of the obligation due from a subject to a prince.
• noun Fealty has escaped less completely from this earliest sense, but has a permissible use in the sense of fidelity under obligation of various kinds.

from the GNU version of the Collaborative International Dictionary of English.

• noun The tie or obligation, implied or expressed, which a subject owes to his sovereign or government; the duty of fidelity to one's king, government, or state.
• noun Devotion; loyalty.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Loyalty to some cause, nation or ruler.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the act of binding yourself (intellectually or emotionally) to a course of action
• noun the loyalty that citizens owe to their country (or subjects to their sovereign)