I came across a new word today, one I simply have to have, because it says something so economically. It's lagniappe and I saw it at Language Log.
It means something thrown in as a free extra. It's pronounced lan-yap and comes from the US, from American French, via American Spanish, from Quechua.
Merriam-Webster dates it from 1844
I'll be looking for a chance to use it.