noun

the quality of not being loyal to a person, country, or organization; unfaithfulness.

an accusation of disloyalty and betrayal

unfaithfulness,infidelity,inconstancy,faithlessness,fickleness,unreliability,untrustworthiness,breach of trust,breach of faith,betrayal,falseness,false-heartedness,falsity,duplicity,double-dealing,treachery,perfidy,perfidiousness,treason,subversion,sedition,dissidence,adultery,back-stabbing,two-timing,hollow-heartedness,Punic faith,recreancy