Right.

The tip is not physically thicker than the root, but RELATIVELY thicker for it's airfoil length. I'm guessing that since this was a "freestyle wing" (first post) that this was done to reduce the sharpness of the stall, unlike a typical Pattern ship.

...the symmetrical wing-equivalent of washout.

Perhaps Ollie or someone who is more expert in these matters can clarify it better, but that's my impression.