Oblivion (noun)

1. The state of being completely forgotten or unknown.
2. The state of being unaware or unconscious.

Origin:

From latin obliviō, from obliviscor "forget", from ob- "completely" + *leuisc- "forget".

Examples:

1. The small town fell into oblivion after the war.
2. The inventor's name has been consigned to oblivion.
3. She drank herself into oblivion every night.
4. The city was destroyed and sank into oblivion.
5. The company's failure led to its slide into oblivion.