half a brain

all over hell's half acre

All over the place; everywhere.

baker's half dozen

Seven, a group of seven.

beat one's brain

To struggle to think or remember something.

bend the brain

To be difficult to comprehend.

bird of one's own brain

One's own idea or conception.

brain blast

The moment of a sudden unexpected discovery.

brain bucket

A protective helmet, as worn, for example, by a motorcyclist, bicyclist, or soldier in combat.

brain candy

A narrative, commentary, etc. which amuses and holds one's attention, but which lacks intellectual depth or importance.