brain-damaged

Adjective

 * 1) Suffering from an injury to the brain.

Etymology 2
Generalization of “Honeywell Brain Damage” (HBD), a notional disease invented to explain certain poor design decisions in Honeywell Multics.

Adjective

 * 1)   designed; obviously wrong.

Usage notes

 * This is a harsh insult, suggesting that the mistake is so egregious that only a brain-damaged person could have committed it.