faithless: applies to any failure to keep a promise or pledge or to any breach or betrayal of obligation, allegiance, or loyalty: ~ allies refused to support the sanctions.   (pledge保证誓言: a serious promise严肃的诺言a pledge of support许诺支援)   (breach违背诺言: breach of contract违反合同)


false: stresses the fact of failing to be true in any manner or degree ranging from fickleness to cold treachery: betrayed by ~ friends.   (fickle多变善变: the group has been notoriously fickle in the past这伙人过去出了名的善变) (treachery随时背叛: 随时准备背叛，本组倒数第二个)


disloyal: implies a lack of complete faithfulness in thoughts or words or actions to a friend, cause, leader, or country: accused the hostages of being ~ to their country.


traitorous: implies either actual treason or a serious betrayal of trust: ~ acts punishable by death.


treacherous: implies readiness to betray trust or confidence: the victim of ~ allies.


perfidious: adds to treacherous the implication of an incapacity for fidelity or reliability and of baseness or vileness: repeated and ~ violations of the treaty.   (base和vile分别表示一般下劣和极端下劣,和low(介于之间)组成一组同义词，应该不难记)   treaty公约


faithless背信弃义: 泛指任何违背诺言或违反忠诚效忠义务，false虚假: 泛指不真实，从多变到随时背叛，disloyal不忠诚: 不是完全忠诚，语气稍弱可轻可重，traitorous叛徒的叛国的: 叛国或严重背叛，treacherous随时背叛: 表示随时准备背叛信任，perfidious无法忠诚: 增加了无法忠诚的意思，程度最重


记忆方法: 1) 首字母FFDTTP重组成Ta Fan Fu De Pian Ta他反复地骗他<==不忠诚

         2) 不忠的意思是不忠诚效力 mean untrue to someone or something that has a right to expect fidelity or allegiance.首字母FFDTTP重组成Ta Fan Fu De Pian Ta他反复地骗他<==不忠诚