perfidy per-through 通過，穿過
Deliberate breach of faith; calculated violation of trust; treachery
The act or an instance of treachery.
n. 不誠實；背信棄義

perfidious
Of, relating to, or marked by perfidy; treacherous
adj. 背信棄義的；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；精確；忠誠；盡責

例句：
People have failed to act in fidelity to their vows.
人們沒能忠誠地履行自己的誓言。

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

耶魯公開課 - 金融市場課程節選
When you serve on a board, you are in a fiduciary role; you are there to protect shareholders and that's the concept.
一旦你進入了董事會,你就成為了受托人,你的存在就是為了維護股東的利益,就是這樣。

allegiance

詞匯起源
[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，忠誠；忠貞

例句：
My allegiance to Kendall and his company ran deep.
我對肯達爾和他的公司的擁戴持久深厚。

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，領主；君主忠實的臣民
adj. 君主的；君臣關系的，忠誠的；臣服的