Millenium or Millennium ?

Millennium

Exemple : ‘’I was alive to see the millennium.’’

The word "millennium" is written with both a double letter "l" and "n." It derives from the Latin word of the same spelling. The "mill" denotes the word "thousand" and the suffix "ennium" is used in order to denote the word "year." This suffix originates from the Latin word for year, "annus."