Adverb similar to 'a lot', yet used when you are definitely sure about it.
I love you extra-much.
That freaked me out extra-much.
Acronym for: Hate It Soo Much, similar to the popular text or blogging acronym, SMH, but with more feeling of annoyance and/or hatred.
Guy when texting:
Guy: yo bro, i got an xtra tickt 2 the JayZ concert this sat. u in?
Friend: i gotta work...HISM arrrggghhh!!!