lenient vs leniency

lenient is not a noun while leniency is a noun.

Word	Noun	Adjective	Verb	Adverb
lenient	No	Yes	No	No
leniency	Yes	No	No	No

lenient (noun)	leniency (noun)
	lightening a penalty or excusing from a chore by judges or parents or teachers
	mercifulness as a consequence of being lenient or tolerant
	a disposition to yield to the wishes of someone

lenient (adjective)	leniency (adjective)
characterized by tolerance and mercy
tolerant or lenient
not strict