boring vs irksome

boring is a noun but irksome is not a noun.

Word	Noun	Adjective	Verb	Adverb
boring	Yes	Yes	No	No
irksome	No	Yes	No	No

As adjectives, boring and irksome are synonyms defined as:

Other synonyms of boring include deadening, dull, ho-hum, slow, tedious, tiresome, wearisome.

boring (noun)	irksome (noun)
the act of drilling a hole in the earth in the hope of producing petroleum
the act of drilling

boring (adjective)	irksome (adjective)
so lacking in interest as to cause mental weariness	so lacking in interest as to cause mental weariness