You could also watch this video: <a href="https://www.youtube.com/watch?v=6GtWfXESskQ" rel="noopener noreferrer" target="_blank">https://www.youtube.com/watch?v=6GtWfXESskQ</a>; (Explaining the Many Names of Germany/Deutschland/Allemagne etc.)

That's a very interesting question. As I had no idea why is it so I decided to google it. It turns out that every of that word is an orignal one, because Germany was a new country in 1872.

Here's more detailed explanation https://www.quora.com/Why-is-the-word-Germany-so-different-in-other-languages

btw, I think you ask very interesting questions on italki

In Arabic, too, the word for “German” is very different. الألمانية (pron.: al-almaniyya). Kind of interesting.

I've also found out it is 'saksa' in Estonian, 'vācu' in Latvian, and 'Vokiečių' in Lithuanian.

damngoodadvice, it is likely from French. The Slavic word was borrowed in Arabic as a name of Austria, "nimtsa".