lunacy vs indulgence

lunacy and indulgence both are nouns.

Word	Noun	Adjective	Verb	Adverb
lunacy	Yes	No	No	No
indulgence	Yes	No	No	No

As nouns, lunacy and indulgence are synonyms defined as:

Other synonyms of lunacy include craziness, folly, foolery, tomfoolery.

lunacy (noun)	indulgence (noun)
foolish or senseless behavior	the act of indulging or gratifying a desire
obsolete terms for legal insanity	foolish or senseless behavior
	the remission by the pope of the temporal punishment in purgatory that is still due for sins even after absolution
	an inability to resist the gratification of whims and desires
	a disposition to yield to the wishes of someone