1 definition by A-non-e-moose.

Top Definition

A girl who is only kept dangling by a guy whilst pursuing another, more attractive girl. Usually to have sex with when things go wrong.

My girlfriend was a "backup girl" before she met me.

"Are you dating her?"
"Nah man, she's just my backup girl."

by A-non-e-moose. October 19, 2008