unknown vs depreciation

unknown and depreciation both are nouns.

Word	Noun	Adjective	Verb	Adverb
unknown	Yes	Yes	No	No
depreciation	Yes	No	No	No

unknown (noun)	depreciation (noun)
a variable whose values are solutions of an equation	a decrease in price or value
an unknown and unexplored region	a communication that belittles somebody or something
anyone who does not belong in the environment in which they are found	decrease in value of an asset due to obsolescence or use

unknown (adjective)	depreciation (adjective)
not known
being or having an unknown or unnamed source
not famous or acclaimed
not known before
not known to exist