lack vs stringency

lack and stringency both are nouns.

Word	Noun	Adjective	Verb	Adverb
lack	Yes	No	Yes	No
stringency	Yes	No	No	No

As nouns, stringency is a hyponym of lack; that is, stringency is a word with a more specific, narrower meaning than lack:

lack: the state of needing something that is absent or unavailable
stringency: a state occasioned by scarcity of money and a shortage of credit

Other hyponyms of lack include absence, dearth, famine, shortage, deficit, mineral deficiency, shortness, tightness.

lack (noun)	stringency (noun)
the state of needing something that is absent or unavailable	conscientious attention to rules and details
	a state occasioned by scarcity of money and a shortage of credit

lack (verb)	stringency (verb)
be without
To be insufficiently prepared