What is Drop And Unload?
1.
To drop your pants, masturbate, and end with orgasm.
(Inner Monologue): Oh god, she's so hot, I just want to drop and unload right here!
2.
To drop your pants then to masturbate with the sole purpose of ejaculating.
"Dude, do you feel heavy?"
"Dude, yeah."
"Dude, drop and unload, and see if you feel lighter."
3.
to deliver goods to a store
"ok, drop and unload these at the main warehouse"