From the city of Weimar, where the constitution of the republic was resolved.

It was a nickname. In 1919 the new German constitution was worked out in Weimar, Thuringia.

Article 48 of the Weimar constitution allowed the president to rule by decree at times of an emergency and gave the president the right to override the Reichstag and provide leadership "above party".
Article 48 of the Weimar constitution made provision for rule by decree in an emergency.

A great many delegates from all over Germany attended the convention in Weimar in 1919 to help create a new constitution. The primary author of the constitution was Hugo Preuss, an attorney and liberal politician. Preuss was also a Jew, a fact that the Nazis were able to use to their advantage during their later campaigns to replace the Weimar Republic with an authoritarian Nazi state.