natural philosophy vs fiducial

natural philosophy is a noun but fiducial is not a noun.

Word	Noun	Adjective	Verb	Adverb
natural philosophy	Yes	No	No	No
fiducial	No	Yes	No	No

natural philosophy (noun)	fiducial (noun)
the science of matter and energy and their interactions

natural philosophy (adjective)	fiducial (adjective)
	relating to or of the nature of a legal trust (i.e. the holding of something in trust for another)
	used as a fixed standard of reference for comparison or measurement
	based on trust