- accepted as a fixed basis of reference or comparison: a fiducial point; a fiducial temperature.
- based on or having trust: fiducial dependence upon God.
- physics used as a standard of reference or measurementa fiducial point
- of or based on trust or faith
- law a less common word for fiduciary
1570s, from Latin fiducialis “reliable,” from fiducia “trust” (see faith).