Sort:  

"Irregardless is a word commonly used in place of regardless or irrespective, which has caused controversy since the early twentieth century, though the word appeared in print as early as 1795"
https://en.wikipedia.org/wiki/Irregardless

I'm old. lol

OMG. Not in the dictionary but in wikipedia and they call it a word.
As old as 18th century even.

Wait... i will find it. My Hero