noun

disloyalty

dis-LOY-ul-tee/dɪsˈlɔɪəlti/

Lack of faithfulness to someone or something owed support.

The husband's disloyalty shows as he secretly holds another woman's hand behind his chair.

At a small café table, a man holds his wife's hand openly while secretly interlacing his other hand with another woman's behind his chair.

Etymology

disOld Frenchnot; opposite of

+loyalLatinpertaining to the law

+tyOld Frenchstate or quality

The law-related base developed the sense of being honorable and faithful. The negative prefix and noun ending turn that quality into its absence: a failure of faithfulness, especially a violation of allegiance or duty.

In context

Human Capital Innovations2:02

Fear of looking foolish, of being difficult, of not being a team player. People worry about being sidelined, getting poor reviews, even losing their jobs. In many cultures, dissent equals disloyalty.

Why Unanimous Meetings Fail: The Hidden Danger of Consensus

More examples

Disagreeing with a friend does not always show disloyalty.
She accuses him of disloyalty for sharing company secrets.
His disloyalty to the team costs him their trust.

Forms

disloyalty · disloyalties

disloyal adjective — Not faithful to someone or something owed support.

Similar words

betrayal: Betrayal emphasizes a specific act that breaks someone's trust.
unfaithfulness: Unfaithfulness often concerns broken promises, especially in romantic relationships.