the title of the Holy Roman Emperors or the emperors of Austria or of Germany until 1918
"The kaiser's decree was signed in Berlin before the empire fell."
Alternative form of Kaiser.
"The kaiser who abdicated in 1918 was Wilhelm II, marking the end of the German Empire's monarchy."
An emperor of a German-speaking country, particularly the Holy Roman Empire (962–1806), the Austrian Empire (1806–1918), or the German Empire (1871–1918) — often specifically Wilhelm II — or (rarely) any emperor.
In plain English: A kaiser is an old-fashioned German word for emperor, which was once used as a title for powerful rulers of Germany and Austria-Hungary.
"The students were excited to learn about history when their teacher mentioned Kaiser Wilhelm II in her lecture on Germany's past."
A surname.
"The Kaiser family has owned that historic bakery in Berlin for three generations."
The word kaiser came into English through the Middle English term kayser and originates in Old High German, where it originally meant "emperor." It traveled to England as a title for powerful rulers rather than retaining its exact original meaning unchanged.