Its source is an Old Norse expression meaning "Old age."
This girl's name is used in Norwegian, Swedish and Danish.
The name Elli ranked 4249th in popularity for females of all ages in a sample of the 1990 US Census.
In Norse mythology, Thor wrestled an old woman with this name and lost. The trickster Loki later told Thor he didn't have a chance aginst Elli because she was Old Age in disguise, and old age conquers all.