adj.
Pronunciation: ' f ā th-l ə s
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>.