A douchebanger is a girl who repeatedly has sex or hooks up with complete douchebags. She
may be slightly aware or completely in denial. She does it on a
regular basis, and has not been
well exposed to other types of men... normal guys who have manners, normal taste in clothing, and know how to treat a lady
"
Wow she's such a douchebanger, I can't believe she's going home with that douche-
sack."
Girls who usually have low sel-esteem or think they know what is "cool" sleep with douchebags. Therefore, she is a douchebanger.