Obergruppenfuhrer
Obergruppenführer (German: [ˈoːbɐˌɡʁʊpn̩fyːʁɐ], "senior group leader") was one of the Third Reich's paramilitary ranks, first created in 1932 as a rank of the Sturmabteilung (SA), and adopted by the Schutzstaffel (SS) one year later.
I came upon this word in Donna Tartt’s The Goldfinch. I had some idea of what it meant, because of the etymology of the word fuhrer, but I didn’t know the full meaning.
The History Channel has a short video on the rise of the Nazis on YouTube that’s pretty interesting.
If you want to know how this word is pronounced, you can go here to listen to it and practice your own pronunciation.