Tending to betray; especially having a treacherous character as attributed to the Carthaginians by the Romans:
— The perfidious Judas.

synonyms: punic, treacherous.

Roget 544: false, deceitful, mendacious, unveracious, fraudulent, dishonest, faithless, truthless, trothless; unfair, uncandid; hollow-hearted; evasive; uningenuous, disingenuous; hollow, sincere, Parthis mendacior; forsworn.    artificial, contrived; canting; hypocritical, jesuitical, pharisaical; tartuffish; Machiavelian; double, double tongued, double faced, double handed, double minded, double hearted, double dealing; Janus faced; smooth-faced, smooth spoken, smooth tongued; plausible; mealy-mouthed; affected etc. 855.    collusive, collusory; artful etc. (cunning) 702; perfidious etc. 940; spurious etc. (deceptive) 545; untrue etc. 546; falsified etc. v.; covinous.    ... show more

Roget 940: dishonest, dishonorable; unconscientious, unscrupulous; fraudulent etc. 545; knavish; disgraceful etc. (disreputable) 974; wicked etc. 945.    false-hearted, disingenuous; unfair, one-sided; double, double-hearted, double-tongued, double-faced; timeserving^†, crooked, tortuous, insidious, Machiavelian, dark, slippery; fishy; perfidious, treacherous, perjured.    infamous, arrant, foul, base, vile, ignominious, blackguard.    contemptible, unrespectable, abject, mean, shabby, little, paltry, dirty, scurvy, scabby, sneaking, groveling, scrubby, rascally, pettifogging; beneath one.    low-minded, low-thoughted^†; base-minded.    undignified, indign^†; unbecoming, unbeseeming^†, unbefitting; derogatory, degrading; infra dignitatem [Lat.], beneath one's dignity; ungentlemanly, ungentlemanlike; unknightly^†, unchivalric^†, unmanly, unhandsome; recreant, inglorious.    corrupt, venal; debased, mongrel.    faithless, of bad faith, false, unfaithful, disloyal; untrustworthy; trustless, trothless^†; lost to shame, dead to honor; barratrous.    ... show more