Definitions

1. noun

a person or thing that is dark or obscure, especially a shadowy figure of evil or death

“In mythology, Erebus was the personification of darkness and shadow.”

2. proper noun

the name of the son of Chaos in Greek mythology, father of Nyx and father of Aether and Hemera, and in astronomy, the name of the southernmost constellation

“The ancient Greeks believed that Erebus was the first darkness in the universe.”