In Vietnamese it means "Satan" or "Devil" or "Lord of the Underworld" or perhaps "Ghost"? It can be used as a singular or in conjunction with other phrases or words.
Con me may. Di o voi ong ma quy di! - Mother fucker (Yo mama). Why don't you go to hell or go live with Satan/Devil!
Ong ma quy! - A ghost!
Ong ma quy! - A ghost!
by Angry Gook April 8, 2012