look up any word, like blumpkin:
 
1.
It is when you profoundly understand something.

To undersee something is to get out of that fugue state-of-mind and simply see something for what it is instead of, the inferior, understanding what's going on.
Dude 1: "... And that's how it all happened."
Dude 2: "Dude... DUDE!"
Dude 1: "Yeah?"
Dude 2: "Not only do I understand... I UNDERSEE IT!"
Dude 1: "Dude, that's wicked. Lets smoke a J."
by Smooth Dog January 14, 2012