indecision vs irresolution

indecision and irresolution both are nouns.

Word	Noun	Adjective	Verb	Adverb
indecision	Yes	No	No	No
irresolution	Yes	No	No	No

As nouns, irresolution is a hypernym of indecision; that is, irresolution is a word with a broader meaning than indecision:

indecision: the trait of irresolution; a lack of firmness of character or purpose
irresolution: the trait of being irresolute; lacking firmness of purpose

Other hypernyms of indecision include irresoluteness.

As nouns, indecision and irresolution are synonyms defined as:

indecision and irresolution: doubt concerning two or more possible alternatives or courses of action

Other synonyms of indecision include indecisiveness.

indecision (noun)	irresolution (noun)
the trait of irresolution; a lack of firmness of character or purpose	the trait of being irresolute; lacking firmness of purpose
doubt concerning two or more possible alternatives or courses of action	doubt concerning two or more possible alternatives or courses of action