brain damage n.
Injury to the brain that is caused by various conditions, such as head trauma, inadequate oxygen supply, infection, or intracranial hemorrhage, and that may be associated with a behavioral or functional abnormality.
1. [generalisation of "Honeywell Brain Damage" (HBD), a theoretical disease invented to explain certain utter cretinisms in Honeywell Multics] Obviously wrong; cretinous; demented. There is an implication that the person responsible must have suffered brain damage, because he should have known better. Calling something brain-damaged is really bad; it also implies it is unusable, and that its failure to work is due to poor design rather than some accident. "Only six monocase characters per file name? Now *that's* brain-damaged!"
2. [especially in the Mac world] May refer to free demonstration software that has been deliberately crippled in some way so as not to compete with the commercial product it is intended to sell. Synonym crippleware.
[Jargon File]