hesitation vs irresolution

hesitation and irresolution both are nouns.

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

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

hesitation: indecision in speech or action
irresolution: doubt concerning two or more possible alternatives or courses of action

Other hypernyms of hesitation include indecision, indecisiveness.

hesitation (noun)	irresolution (noun)
the act of pausing uncertainly	the trait of being irresolute; lacking firmness of purpose
a certain degree of unwillingness	doubt concerning two or more possible alternatives or courses of action
indecision in speech or action