mindmap root((不忠)) 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. false stresses the fact of failing to be true in any manner or degree ranging from fickleness to cold treachery: betrayed by ~ friends. disloyal implies a lack of complete faithfulness in thoughts or words or actions to a friend, cause, leader, or country: accused the hostage of being ~. 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公约. (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)