Etymology: probably blend of irrespective and regardless
Date: circa 1912
nonstandard : REGARDLESS
usage Irregardless originated in dialectal American speech in the early 20th century. Its fairly widespread use in speech called it to the attention of usage commentators as early as 1927. The most frequently repeated remark about it is that "there is no such word." There is such a word, however. It is still used primarily in speech, although it can be found from time to time in edited prose. Its reputation has not risen over the years, and it is still a long way from general acceptance. Use regardless instead.
Husband: "Kiss my ass bitch! I'm still going to the strip club tonight!"
Irregardless is a non-word that many a tool mistakenly believe to be correct usage in formal style, when in fact it is used chiefly in nonstandard speech or uneducated writing. Coined in the United States in the early 20th century, it has met with a blizzard of condemnation for being an improper yoking of irrespective and regardless and for the logical absurdity of combining the negative ir- prefix and -less suffix in a single term. Although one might reasonably argue that it is no different from words with redundant affixes like debone and unravel, it has been considered a blunder for decades and will probably continue to be so.
To be honest, I dont mind people using words like this in normal speech, but I cant stand to see it in print. People like journalists and authors, I believe, have a responsibility to be at least somewhat gramatically correct.
Other person: "Alot of words are considered ungrammatical before they are sanctioned."
Me: "Yes, and it's a sad testiment to the quality of education in society when these mistakes are sanctioned!"