The Reichssicherheitshauptamt (RSHA) was the main division of the Nazi SS, and the parent organization of the Gestapo. The German word "Reich" is untranslatable, but you couldn't come closer in contemporary English than the emotionally-laden term "homeland." "Sicherheit" is always translated as "security," and "Hauptamt" literally means "main office," which in the American government, we call a "department."