A nevermore is something that will no longer exist or happen again.
The word "nevermore" is often used in phrases like "abandon all hope, ye who enter here" or simply to convey a sense of finality. Imagine someone you loved has passed away and their things have been left behind - it's as if they are never going to be seen or experienced by you again. In Edgar Allan Poe's famous poem, "The Raven," the word is used to describe a lost love that can never be regained.
Never again.
