mortal sin vs rapacity

mortal sin and rapacity both are nouns.

Word	Noun	Adjective	Verb	Adverb
mortal sin	Yes	No	No	No
rapacity	Yes	No	No	No

As nouns, rapacity is a hyponym of mortal sin; that is, rapacity is a word with a more specific, narrower meaning than mortal sin:

mortal sin: an unpardonable sin entailing a total loss of grace
rapacity: reprehensible acquisitiveness; insatiable desire for wealth (personified as one of the deadly sins)

mortal sin (noun)	rapacity (noun)
an unpardonable sin entailing a total loss of grace	reprehensible acquisitiveness; insatiable desire for wealth (personified as one of the deadly sins)
	extreme gluttony
	(of an animal, usually a bird) The quality of subsisting off live prey.