I think it means that basically no matter how much you brush your teeth and whatnot you'll have bad breath... I'm not sure how to tell you if you have it but if you find out you do I recommend carrying around mints and mint gum (provided you even like them) ...
You mean halitosis? Or just plain ol yucky haven't-brushed-your-teeth breath? See your dentist, he'll tell you if there's something up. If you brush your teeth/tongue and floss and your breath still stinks, I'd be concerned.