short for customers in the service industry. particularly those viewed with disdain by servers.
"i wish these custies would back the fuck off."
"If I get one more order for another latte, I'm gonna pop a cap in a custies ass"
Short for customs.
"Nigga is you crazy? You aint makin it through custies with a suitcase full of blow"
"Man.. I just got popped tryin to smuggle some dope through custies"