When smoking J's, on deck is that who is ready to spark the next one. He/she does this by placing the J that will be smoked on top of their ear.
Alright, I could smoke another one, who's on deck?
Look at you, always on deck!
What's that shit on your ear? Oh, you're on deck.
To have something readily available or within reach.
I keep them choppas on deck!
Bitch I got stacks on deck!
To be in possession of narcotics with intention to distribute.
"Pico, this fool around the corner needs an eightball. You on deck?"
"Yea, I'm packin.' Lemme go scale dis shit."
when a hustla has his product of choice ready to sell
i got dvds, cds, & dro on deck
To be in possession of drugs with the intent to sell.
"Hey, where can I find some weed?"
"Mitch is on deck."
-I need to get faded.
-Talk to Jay, hes always on deck
Can be used as a question or statement of who is or should be next or aks the question of what's coming up.
This phrase is an old shipping term. It was used to find out who was or was supposed to be on guard, doing duties, etc. This term later moved into the realm of baseball and is still used to this day as a description of who's going to be batting next.
"Let's get this line move'n people. Who's on deck?"
next person to bat in a baseball game
"Giambi is needs a double
here in the sixth. If not, then the Yanks will have to count on Jeter whose on deck."