I foresee you're going to be a pain in my ass in the future, irregardless of spam, seeing as how you can't read the forum description and ban you in advance.
It's just a word I've been using since I was like 16 lol, too lazy to say regardless (not that it's easier, just that it requires me to think to change it or use it in place of most days) and 90% of the time I try to type regardless it comes out as irregardless *shrug*. Also, as Broken mentioned, it's essentially slang, using the term literally (and thus basically meaning it is the opposite of regardless, ie it means something worth regard) then of course it will come up as being a false form of speech, but it's no worse than some ****** running into the room with a do-rag on scream 'yo dawg, my shizzle is fizzle'. Except... you know.... not as stupid, or black.
Technically, in the english lanauge, you can create words by adding prefixes and suffixes. As long as it makes sense.
