A motorcycle helmet. Specifically the kind that just covers the top of your head. They are mostly sported by riders on top of a American brand motorcycle, chiefly, Harley Davidson.
Hey Pete, good thing you were wearing your brain pan when that car slammed you. Your face is a mess but at least you can think straight!
by WindowLicker9000 April 11, 2010
1 more definition
The part of the skull that encloses the brain.
Bullet to the brainpan. Squish.
by Skalman January 13, 2010