1. The condition of apparently limitless or endless time: When the couple traveled from Marburg to Berlin, there seemed to be an eternity of delays caused by innumerable construction sites on the freeway.
2. The status of immortality: Jane's mother had passed away the year before and was in the realm of eternity.
3. An existence that never ends: Since Mary knew that plants and animals died, she thought that rocks, stones, and boulders would be extant on Earth into eternity.