Pre-dab

A dab that is performed before the absolute completion of a task. This can be anything from dabbing after finishing an exam but before turning it in to dabbing after throwing a basketball but before it goes through the hoop. It's a form of claiming victory beforehand and asserting dominant confidence in a situation, but is very risky. Upon a pre-dabbing, one signs up for the risk of looking like an absolute idiot when the task fails.

Person A: "Dude, no way that grenade will land in the right spot."
Person B: "Just watch."
Person B throws a grenade in game out of sight behind a structure. Person B dabs preemptively, and the dab is shortly followed with the notification that he has successfully killed an enemy.
Person A: "HOLY SHIT DUDE! YOU EVEN DID A PRE-DAB HOW DID YOU KNOW IT WOULD LAND??"
Person B: "What did I tell you man? I got this."

Pre-dabbing

A dab that is taken before a dab. In example when someone pre-games with alcohol before a party.

A dab taken before the final dab.
A Marijuana wax, rosin, oil and etc.

"I'm pre-dabbing my before I take join the dab sesh"
"Let's pre-dab by taking a few dabs and then well take our final dab"