fiduciary

Short definition from Wiktionary

Adjective

1. 1
   Relating to an entity that owes to another good faith, accountability and trust, often in the context of trusts and trustees.
2. 2
   Pertaining to paper money whose value depends on public confidence or securities.
3. 3
   Accepted as a trusted reference such as a point, value, or marker; fiducial.

Noun

1. 1
   One who holds a thing in trust for another.
2. 2
   One who depends for salvation on faith, without works; an antinomian.