1. unfaithful(a = adj.all) - not true to duty or obligation or promises; "an unfaithful lover"
Antonym: faithful
Derived form noun unfaithfulness1
2. unfaithful(a = adj.all) - having sexual relations with someone other than your husband or wife, or your boyfriend or girlfriend; "her husband was unfaithful"
Antonym: faithful
Derived form noun unfaithfulness1
3. unfaithful(s = adj.all) faithless, traitorous, treasonable, treasonous - having the character of, or characteristic of, a traitor; "the faithless Benedict Arnold"; "a lying traitorous insurrectionist"
Derived form noun unfaithfulness1
4. unfaithful(s = adj.all) - not trustworthy; "an unfaithful reproduction"
1. Not faithful; not observant of promises, vows, allegiance, or duty; violating trust or confidence; treacherous; perfidious; as, an unfaithful subject; an unfaithful agent or servant. [1913 Webster]
"My feet, through wine, unfaithful to their weight." [1913 Webster]
"His honor rooted in dishonor stood,
And faith unfaithful kept him falsely true." [1913 Webster]
2. Not possessing faith; infidel. Milton. [1913 Webster]
unfaithful, adj.
1 not faithful, esp. adulterous.
2 not loyal.
3 treacherous.
Derivative:
unfaithfully adv. unfaithfulness n.
N improbity, dishonesty, dishonor, deviation from rectitude, disgrace, fraud, lying, bad faith, Punic faith, mala fides, Punica fides, infidelity, faithlessness, Judas kiss, betrayal, breach of promise, breach of trust, breach of faith, prodition, disloyalty, treason, high treason, apostasy, nonobservance, shabbiness, villainy, villany, baseness, abjection, debasement, turpitude, moral turpitude, laxity, trimming, shuffling, perfidy, perfidiousness, treachery, double dealing, unfairness, knavery, roguery, rascality, foul play, jobbing, jobbery, graft, bribery, venality, nepotism, corruption, job, shuffle, fishy transaction, barratry, sharp practice, heads I win tails you lose, mouth honor, dishonest, dishonorable, unconscientious, unscrupulous, fraudulent, knavish, disgraceful, wicked, 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, 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, dishonestly, mala fide, like a thief in the night, by crooked paths, Int, O tempora!, O mores!, corruptissima respublica plurimae leges.