sinking fund vs monetary fund

sinking fund and monetary fund both are nouns.

Word	Noun	Adjective	Verb	Adverb
sinking fund	Yes	No	No	No
monetary fund	Yes	No	No	No

As nouns, monetary fund is a hypernym of sinking fund; that is, monetary fund is a word with a broader meaning than sinking fund:

sinking fund: a fund accumulated regularly in a separate account and used to redeem debt securities
monetary fund: a reserve of money set aside for some purpose

Other hypernyms of sinking fund include fund.

sinking fund (noun)	monetary fund (noun)
a fund accumulated regularly in a separate account and used to redeem debt securities	a reserve of money set aside for some purpose