Well okay, according to Merriam-Webster it is actually a word. Just not a very good one.
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.
So, while I’ve always heard and gone with the explanation that “irregardless is not a word,” I can admit I was wrong.
But, it’s still not proper word usage. And the fact that I heard it used multiple times in business meetings over the past few days sort of gets on my nerves.
Grammar Girl says:
Language experts speculate that irregardless comes from a combination of the words regardless and irrespective and that another reason people might say “irregardless” is that they are following the pattern of words like irregular and irreplaceable. But regardless already has the -less suffix on the end, so it’s not like those other words.
As a writer, there are times I take liberty with the language for effect. Sometimes for shock value (see, that was a sentence fragment). But in the general context of speech and writing, particularly in business, that’s just not acceptable.
So, my take on it? Don’t use the word.
Irregardless of your reasons.