Any of several species of coral with the appearance of a brain, in the families Mussidae and Merulinidae.

Any mass educational system of improving or providing conditions to increase the intellectual quality and yield of a population of (human) brains, e.g. a university or school.

Alternative form of harebrained

(figuratively, slang, mildly vulgar) Something ill-considered and said or done impulsively. / (figuratively, slang, mildly vulgar) An instance of absent-mindedness or forgetfulness.

(cytology) A cell in the brain, such as a neuron or a glial cell. / (colloquial) neuron / (humorous) -- taken as a unit of intelligence

Synonym of knowledge worker

(obsolete) an impetuous, fiery person; a hothead

impetuous and rash; hot-headed

(medicine) An irreversible loss of brain function and cessation of brain activity.

Alternative spelling of brain-dead