disregardless vs irrespective

disregardless and irrespective both are adverbs.

Word	Noun	Adjective	Verb	Adverb
disregardless	No	No	No	Yes
irrespective	No	No	No	Yes

As adverbs, disregardless and irrespective are synonyms defined as:

disregardless and irrespective: in spite of everything; without regard to drawbacks

Other synonyms of disregardless include disregarding, no matter, regardless.

disregardless (adverb)	irrespective (adverb)
in spite of everything; without regard to drawbacks	in spite of everything; without regard to drawbacks