irritant vs nuisance

irritant and nuisance both are nouns.

Word	Noun	Adjective	Verb	Adverb
irritant	Yes	No	No	No
nuisance	Yes	No	No	No

As nouns, nuisance is a hypernym of irritant; that is, nuisance is a word with a broader meaning than irritant:

Other hypernyms of irritant include annoyance, bother, botheration, infliction, pain, pain in the ass, pain in the neck.

irritant (noun)	nuisance (noun)
something that causes irritation and annoyance	(law) a broad legal concept including anything that disturbs the reasonable use of your property or endangers life and health or is offensive
	something or someone that causes trouble; a source of unhappiness