Someone who can one-up hustling. Like hustlers they get money, bitches and drugs but in a different way. They try to broaden all the topics and gain them at once. A grustler doesn't care about anyone but themselves and they tend to make friends just to use them for money or certain protection. They can persuade very easily. They strive for money in the most hustling of ways.
Grustler1: "I sell weed out of my candy store so people will buy weed and candy." two birds one stone.
Grustler2: "I pimp bitches that pimp bitches and each one of them sell drugs, so I'm just racking up money." Grustling at it's best.
One who both grinds and hustles.