(slang, derogatory) A fool.

plural of der-brain

(neuroanatomy, anatomy) The part of the brain that connects the spinal cord to the forebrain and cerebrum.

(physics) A hypothetical self-aware entity that arises due to random fluctuations of spacetime.

(informal) A pain in the head from eating or drinking something cold; a cold-stimulus headache / (psychology) Failure to remember something, with the sense that recall is imminent.

plural of brain trust

plural of brains trust

plural of brain fart

plural of brain-washing

Suffering from an injury to the brain.