# millionennium

> English word · Noun

## Definitions
1. Synonym of mega-annum: a period of time consisting of one million years.

## Etymology
Blend of million + millennium.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/millionennium