mortal sin vs ira

mortal sin and ira both are nouns.

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

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

mortal sin: an unpardonable sin entailing a total loss of grace
ira: belligerence aroused by a real or supposed wrong (personified as one of the deadly sins)

mortal sin (noun)	ira (noun)
an unpardonable sin entailing a total loss of grace	belligerence aroused by a real or supposed wrong (personified as one of the deadly sins)