Also found in: Medical.
1. A helmet to protect the head and brain, as worn by (e.g.) skateboarders, motorcyclists, soldiers, etc. It may not be fashionable, but if you wear your brain bucket when you ride your motorcycle, it may just save your life. We've experienced a lot of heavy fire in this region, so all soldiers are required to wear their brain buckets at all times in the field.
2. dated One's skull. She received a knock to her brain bucket after she slipped on the stairs.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
n. a bike or motorcycle helmet. (see also skid-lid.) He refuses to wear a brain bucket when he rides.
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.