Definition: Nonstandard Form of Regardless
“irregardless is not a word. this nonstandard definition above is GARBAGE. If you say "irregardless" or write it, you are basically confirming that you are a moron.”
—User Comment on "Irregardless," Merriam-Webster.com
Passions run high when the word irregardless enters a conversation. There are few people who would go so far as to argue that it is acceptable for formal discourse (and we label the word nonstandard), but this is not enough for many, who despise the word so much that they feel that dictionaries should refuse to even acknowledge its existence.
However, if a word is used with regularity by a certain number of people, for a certain length of time, to mean a certain and specific thing, it becomes a word, whether we like it or not. And there is no question that irregardless meets the criteria for inclusion in a dictionary of general English usage. Although it has long been thought to have originated in the early 20th century, recent research has shown that irregardless has been used for considerably longer, and may be found as far back as 1795 (and is in regular use throughout the entire 19th century as well).
But death, irregardless of tenderest ties, Resolv’d the good Betty, at length, to bereave.
—City Gazette [Charleston, NC] 23 June 1795
Or is it because the bloodhound spirit of an office-seeker will track any victim so that he can but secure the spoils irregardless of any incumbent, however faithful, honest, or competent he be?
—The Daily Union [Washington, DC] 13 July 1849
The forty-third section, providing that all children (irregardless of color) shall be received into the public schools on pain of fine and imprisonment, was adopted.
—The Times-Picayune [New Orleans, LA] 11 February 1870