Main Entry: faith·less

Pronunciation: \ˈfāth-ləs\

Function: adjective

Date: 14th century

1 : not true to allegiance or duty : treacherous, disloyal <a faithless servant>
2 : not to be relied on : untrustworthy <a faithless tool>

— faith·less·ly adverb

— faith·less·ness noun

synonyms faithless, false, disloyal, traitorous, treacherous, perfidious mean untrue to what should command one's fidelity or allegiance. faithless applies to any failure to keep a promise or pledge or any breach of allegiance or loyalty <faithless allies>. false stresses the fact of failing to be true in any manner ranging from fickleness to cold treachery <betrayed by false friends>. disloyal implies a lack of complete faithfulness to a friend, cause, leader, or country <disloyal to their country>. traitorous implies either actual treason or a serious betrayal of trust <traitorous acts punishable by death>. treacherous implies readiness to betray trust or confidence <a treacherous adviser>. perfidious adds to faithless the implication of an incapacity for fidelity or reliability <a perfidious double-crosser>.