perfidy per-through 通过，穿过
Deliberate breach of faith; calculated violation of trust; treachery
The act or an instance of treachery.
n. 不诚实；背信弃义

perfidious
Of, relating to, or marked by perfidy; treacherous
adj. 背信弃义的；不忠的

fidelity 信
Faithfulness to obligations, duties, or observances.
Exact correspondence with fact or with a given quality, condition, or event; accuracy.
The degree to which an electronic system accurately reproduces the sound or image of its input signal.
n. 保真度；精确；忠诚；尽责

例句：
People have failed to act in fidelity to their vows.
人们没能忠诚地履行自己的誓言。

fiduciary
Of or relating to a holding of something in trust for another
Of or being a trustee or trusteeship. Held in trust.
Of, relating to, or being a system of marking in the field of view of an optical instrument that is used as a reference point or measuring scale.
One, such as an agent of a principal or a company director, that stands in a special relation of trust, confidence, or responsibility in certain obligations to others.
adj. 信托的；受信托的；基于信用的
n. 受托人；被信托者

耶鲁公开课 - 金融市场课程节选
When you serve on a board, you are in a fiduciary role; you are there to protect shareholders and that's the concept.
一旦你进入了董事会,你就成为了受托人,你的存在就是为了维护股东的利益,就是这样。

allegiance

词汇起源
[Date: 1300-1400; Language: Old French; Origin: ligeance, from lige 'person you owe loyal service to', from Late Latin laetus 'serf']

[Middle English alligeaunce, alteration of ligeaunce, from Old French ligeance, from lige, liege. See liege.]

Loyalty or the obligation of loyalty, as to a nation, sovereign, or cause.
The obligations of a vassal to a lord
n. 效忠，忠诚；忠贞

例句：
My allegiance to Kendall and his company ran deep.
我对肯达尔和他的公司的拥戴持久深厚。

liege
A lord or sovereign to whom allegiance and service are due according to feudal law.
A vassal or subject owing allegiance and services to a lord or sovereign under feudal law.
A loyal subject to a monarch.
Entitled to the loyalty and services of vassals or subjects
Loyal; faithful.
n. 君主，领主；君主忠实的臣民
adj. 君主的；君臣关系的，忠诚的；臣服的