It's a dominican word in spanish to describe a woman that have been with many guys. Avion in english means plane, air plane. A plane had lots of people, an "avion" girl too.
John: i will date Maria
Mark: are you sure? you make caught an STD, that girl is an avion
Pedro: voy a salir con Maria esta noche
Juan: te vas a tirar al avion del barrio.