A form of indoctrination that forces people to abandon their beliefs in favour of another set of beliefs by conditioning through various forms of pressure or torture

(computing) Any hardware (i.e. handheld, computer, laptop) containing vast amounts of information, which is in constant flux and is important to the owner but not so important as to be stored in wetware.

(derogatory, vulgar slang) Extremely stupid.

(derogatory, vulgar slang) An extremely stupid person.

Surgery on any part of the nervous system, especially the brain; neurosurgery. / (uncountable, idiomatic) Something that is overly complex, detailed or confusing.

(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

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