violation of faith; betrayal of trust; treason.

an act of perfidy, faithlessness, or treason.

noun

constancy , devotion , faithfulness , fidelity , honesty , love , loyalty

noun

betrayal , bunco , corruption , dirty dealing , dirty pool * , dirty trick , dirty work * , disaffection , dodge , double-cross * , double-dealing * , duplicity , faithlessness , fake , falseness , fast shuffle , flimflam * , grift , gyp * , infidelity , perfidiousness , perfidy , put-on , racket * , recreancy , scam * , sellout , shell game * , skin game * , spoof , stab in the back * , sweet talk * , treacherousness , treason , two-timing , whitewash * , disloyalty , false-heartedness , falsity , traitorousness , unfaithfulness , double cross , breach , deceit , dishonesty , foul play , guile , punic faith , trickery , triplicity