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.

Origin of disloyalty

1400–50; late Middle English < Middle French desloiaute, Old French desleaute, equivalent to desleal disloyal + -te -ty2

Synonyms for disloyalty

1. faithlessness, subversion.

Synonym study

1. Disloyalty, perfidy, treachery, treason imply betrayal of trust. Disloyalty applies to any violation of loyalty, whether to a person, a cause, or one's country, and whether in thought or in deeds: to suspect disloyalty in a friend. Perfidy implies deliberate breaking of faith or of one's pledges and promises, on which others are relying: It is an act of perfidy to cheat innocent people. Treachery implies being secretly traitorous but seeming friendly and loyal: In treachery deceit is added to disloyalty. Treason is performing overt acts to help the enemies of one's country or government: Acting to aid a hostile power is treason.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for disloyalty

Contemporary Examples of disloyalty

Historical Examples of disloyalty

  • If she still desired his friendship, there was no disloyalty to Sidney in giving it.


    Mary Roberts Rinehart

  • It was the only thing to do, and yet it seemed almost like disloyalty to Malcolm Dunn.

    Cap'n Warren's Wards

    Joseph C. Lincoln

  • Could it be that Mercy—No; the idea of Mercy's disloyalty to him was really too ridiculous.

    A Son of Hagar

    Sir Hall Caine

  • Papa is all out of sorts with what he terms the disloyalty of the people.

    Rodney, the Ranger

    John V. Lane

  • The machine should tell you that I'm not doing so out of disloyalty.


    Poul William Anderson

British Dictionary definitions for disloyalty


noun plural -ties

the condition or an instance of being unfaithful or disloyal
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for disloyalty

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.

Online Etymology Dictionary, © 2010 Douglas Harper