名詞 expedient:

1. a means to an end; not necessarily a principled or ethical one

形容詞 expedient:

1. serving to promote your interest
2. appropriate to a purpose; practical

1. A clever, expedient way of doing something.
   訣竅做事情的靈巧的，便利的方法
2. As he had forgot his keys, he got into the house by the simple expedient of climbing through the window.
   他由于忘了帶鑰匙，便以簡單的應(yīng)急辦法從窗戶爬進(jìn)屋里。
3. He thought it expedient not to tell his wife where he had been.
   他認(rèn)為不告訴妻子他去過哪里是適宜的。

ex.pe.di.ent

adj.（形容詞）
Appropriate to a purpose.
有利的：與目的相稱的

Serving to promote one`s interest:
出于私利的：用來為自己利益服務(wù)的：
例句：
was merciful only when mercy was expedient.
只有仁慈對自己有利時才是仁慈的

Based on or marked by a concern for self-interest rather than principle; self-interested.
基于私利的：依自身利害而定的，基于私利而非原則考慮的；自私自利
Obsolete Speedy; expeditious.
【廢語】 快速的；倉促的
n.（名詞）
Something that is a means to an end.
對策：達(dá)到目的的方法
Something contrived or used to meet an urgent need.See Synonyms at makeshift
權(quán)宜之計，應(yīng)急手段：為應(yīng)急而設(shè)計或使用的事物參見 makeshift

來源：
Middle English
中古英語
from Latin expediôns expedient- [present participle of] expedore [to make ready] * see expedite
源自 拉丁語 expediôns expedient- [] expedore的現(xiàn)在分詞 [做好準(zhǔn)備] *參見 expedite

【引伸】
expe.diently
adv.（副詞）