(idiomatic, sometimes humorous) A protective helmet, as worn, for example, by a motorcyclist, bicyclist, or soldier in combat. / (dated) The skull.

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

(anatomy, dated) The thalamencephalon.

plural of brain farm

(colloquial) Idiotic

(colloquial) cerebrospinal fluid

Muddled in thought or mind; foolish; stupid.

(informal) overwhelming in a way that prevents coherent thought

(informal, Canada, US) A state in which a new mother is forgetful, absent-minded, or easily distracted.

(neuroanatomy) The part of the brain involved with smelling.