A brain so small that when you shake their head you can hear the brain bouncing off the sides of the skull
The stupid bell brain got punched so hard I could hear his brain echoing inside his head
by darrrrrrrrrr December 17, 2020
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brain - means the head of the penis because it is suppose to look like a brain

it links into bell end ,bell head
"shut up you bell brain"

by <Jamie> February 22, 2008
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