fretfulness vs irritability

fretfulness and irritability both are nouns.

Word	Noun	Adjective	Verb	Adverb
fretfulness	Yes	No	No	No
irritability	Yes	No	No	No

As nouns, fretfulness and irritability are synonyms defined as:

Other synonyms of fretfulness include choler, crossness, fussiness, peevishness, petulance.

fretfulness (noun)	irritability (noun)
an irritable petulant feeling	a disposition to exhibit uncontrolled anger
	excessive sensitivity of an organ or body part
	an irritable petulant feeling