faithless

I

(New American Roget's College Thesaurus)

adj. unfaithful, disloyal, untrue, inconstant, treacherous. See improbity, doubt. Ant., faithful.

II

(Roget's IV) modif.

1. [Not keeping faith]

Syn. disloyal, deceitful, false, traitorous, treacherous, perfidious, unreliable, untrustworthy; see also dishonest 1 , 2 , false 1 .

2. [Unbelieving]

Syn. agnostic, skeptical, dubious; see atheistic .

Syn.- faithless implies failure to adhere, as to an oath or obligation [ a faithless wife ] ; false , in this connection more or less synonymous with faithless , stresses failure in devotion to someone or something that has a moral claim to one's support [ a false friend ] ; disloyal implies a breach of allegiance to a person, cause, institution, etc. [disloyal to one's family ] ; traitorous strictly implies the commission of treason; treacherous suggests an inclination or tendency to betray a trust [ his treacherous colleagues ] ; perfidious adds to the meaning of treacherous a connotation of sordidness or depravity [ a perfidious informer ]

III

(Roget's Thesaurus II) adjective Not true to duty or obligation: disloyal, false, false-hearted, perfidious, recreant, traitorous, treacherous, unfaithful, untrue. See CONTINUE, TRUST.