1. The space of a thousand years, specially that during which Satan is to be bound, and Christ, as some think, is to reign in person on earth.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• millinium,
• millienium,
• milenium,
• mellennium,
• milennium,
• millinenium,
• mellenium,
• milleniuem,
• milleneum,
• millenim,
• milleniom,
• milleninum,
• milleniume,
• millanium,
• milleniums,
• milliennium,
• millinnium,
• millenuium,
• millemnium,
• Illenium

• millennian,
• millenniumism.

The adjective form of the word "millennium" is "millennial".