excitability vs irritability

excitability and irritability both are nouns.

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

As nouns, excitability and irritability are synonyms defined as:

excitability and irritability: excessive sensitivity of an organ or body part

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