Irregardless \ir-i-GAHRD-lis\ , adverb;
1. Nonstandard: Regardless
But, wait! Irregardless isn't a word!!!
I know, it's not a real word because it's a double negative. But, irregardless, people use it all the time. See what I did there?
There is an attestation of this word as far back as 1874 where it is used to mean "regardless." It is generally believed to be a blend of irrespective and regardless, which the Oxford English Dictionary calls both 'non-standard' and 'humorous.'