Today other than "Vatican City" Latin is not an official language anywhere. However when I researched I did find out a few countries Hungary, Croatia, and Poland used Latin into the 19th century.
Could not find out why they dropped the language from there countries. It seemed that was very popular in Hungary.
Do you know why these countries dropped Latin ?
Since Latin is still an official language "Holy See" do they review add new words and have a document defining the language ?
For example "computer", "cell phone" did not exist until the last half of the 20th century. How do new words get adopted ?
You are right - in Hungary - latin was the unique official language till 1844. The educated people used it only - With the Reformation the neologists made an important influence on the hungarian language and one used little by little the hungarian language- as an official language too
Just because Latin was the official language in those countries, doesn't mean that most people spoke it. In fact, for hundreds of years it was in use in most places only by a very few clerics and even the highly educated nobility would rarely have used it.
I think it would be fair to say that its use, in most of Europe at least, was primarily because of the strong influence of the Church and the close association between Church and State for many hundreds of years in many countries.
Incidentally, the language spoken in the Vatican ("Holy See", not "Holly See", and actually refers to the governing body of the Catholic Church, not to the Vatican itself) is Italian, even if the "official" language is still Latin.
As for new Latin words, mostly they tend to be created by Latin nerds - including clerical Latin nerds. At some point, the Vatican approves words (or not) for use in Ecclesiastical Latin. The last dictionary (no doubt someone will correct me if there's a more recent one) of Latin words from the Vatican was published in 2003 and contained around 15,000 new or updated Latin words.
As far as I know (I might be wrong) it's currently up to the "Latin Section" of the Vatican's Secretariat of State: if you don't mind the Italian (I can't find other versions) you can check https://www.vaticannews.va/it/vaticano/news/2019-05/sezione-lettere-latine-la-storia.html for how it came to oversee all Latin affairs. Then again I'd imagine the individual writers (the Pope in primis) are free to add and adapt words in their writing.
New Latin words are created all the time, but there is an issue with arguing over the semantics. For example, the word Car. Some people say it should be autoraeda (auto'matic' carriage), but... I on the other hand, know that Car, is short for Carriage, which comes from a Latin word carrus meaning.... carriage. Ergo, carrus could be the Latin word for car, and even lines up with modern cognates such as the Spanish carro. But, like I said, everyone has an opinion on it.
Recently when Finland presided over the European Union they issued whatever documents/proclamations they published in Latin, too.
I have no idea why those countries dropped Latin. Probably for the same reason that Sweden finally dropped trying to use Latin for international treaties (replaced by French) about 100 years before, around 1750--nobody else was using it.
Recently there was this discussion: 'Latinizing' Modern Words/Concepts, which has links to newer dictionaries, etc. (and if you're really interested I can dig up some others).
Thanks. I was sad when their run ended. See my post/comments in these discussions, among others (they are in chronological order):
OT, but the moose video by Daniel Pettersson linked to in "swedes and moose" is pretty good. What do you think?
Part of the reason for switching to national languages will simply be nationalism. Much of central and eastern Europe was part of larger empires during much or all of the 18th and 19th century, including the three countries you mention. (Poland is a bit more complicated, but in essence, it was dominated by foreign powers).
During the 19th century many of these countries decided they wanted more of a voice and to govern themselves. Part of forming a national identity was to emphasise the use of native languages rather than foreign ones. Hungary in particular fought hard for its independence during this period: there was a revolution and civil war in 1848 (which it lost) but then in 1870 it managed to persuade Austria to elevate its status so it became an equal in the empire, before becoming independent in 1918.
At some point during this process, the local government will have decided that they ought to be using Hungarian, firstly to emphasise that they were a different people from the Austrians, and secondly, to make official documents more accessible to normal people, who didn't speak Latin.