from
The Collaborative International Dictionary of English v.0.48
Fiducial \Fi*du"cial\, a. [L. fiducia trust, confidence; akin to
fides faith. See {Faith}.]
1. Having faith or trust; confident; undoubting; firm.
"Fiducial reliance on the promises of God." --Hammond.
[1913 Webster]
2. Having the nature of a trust; fiduciary; as, fiducial
power. --Spelman.
[1913 Webster]
{Fiducial edge} (Astron. & Surv.), the straight edge of the
alidade or ruler along which a straight line is to be
drawn.
{Fiducial line} or {Fiducial point} (Math. & Physics.), a
line or point of reference, as for setting a graduated
circle or scale used for measurments.
[1913 Webster]