Extradditional
When you expect something to be good, then given something extra added to it, then you receive something in addition to that.
I went to the store for the half off sale, then got an extra 20% off that. Then got an extra 30% off just for having my loyalty card. Got what I wanted damn near free, due to the extradditional discounts.
extraddition
Refers to where ya get yanked back "across da pond" to face da music back in Da States for tacking on unauthorized bonuses and unearned dividends during da course of your employment or other business transactions.
Da term "extraddition" could also refer to someone who's already in dutch in his current locale being grabbed by da authorities in another country to face even more charges for other crimes supposedly committed in said second nation.