loy·al   
adjective
1.
faithful to one's sovereign, government, or state: a loyal subject.
2.
faithful to one's oath, commitments, or obligations: to be loyal to a vow.
3.
faithful to any leader, party, or cause, or to any person or thing conceived as deserving fidelity: a loyal friend.
4.
characterized by or showing faithfulness to commitments, vows, allegiance, obligations, etc.: loyal conduct.