KAISER Meaning of KAISER in English Kai ‧ ser, the /ˈkaɪzəʳ/ BrE AmE noun Wilhelm II, the King of Germany from 1888 to 1918. He was given the ↑ nickname ‘Kaiser Bill’ by the British in World War I. Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012