形容詞 fiducial:

1. relating to or of the nature of a legal trust (i.e. the holding of something in trust for another)
   同義詞：fiduciary
2. used as a fixed standard of reference for comparison or measurement
3. based on trust

fi.du.cial

adj.（形容詞）
Based on or relating to faith or trust.
基于信仰的：基于信仰或信任的，與信仰或信任有關的
Relating to or characteristic of a legal trust; fiduciary.
信用的，信托的：與合法的委托有關的或有此特性的；信托的
Regarded or employed as a standard of reference, as in surveying.
基準的：在測量勘定時認為或作為基準的

來源：
Late Latin fodôci3lis
后期拉丁語 fodôci3lis
from Latin fodôcia [trust]
源自 拉丁語 fodôcia [信任]
from fodere [to trust] * see bheidh-
源自 fodere [對…信賴] *參見 bheidh-

【引伸】
fidu.cially
adv.（副詞）