noun, plural dis·loy·al·ties.
- the quality of being disloyal; lack of loyalty; unfaithfulness.
- violation of allegiance or duty, as to a government.
- a disloyal act.
noun plural -ties
- the condition or an instance of being unfaithful or disloyal
early 15c., from Middle French desloyaulte, from Old French desloiaute, desleauté “disloyalty, faithlessness, marital infidelity,” from desloial (see disloyal). Especially of allegiance to a state or sovereign since c.1600.