A lobotomy was a neurosurgical procedure in which the connections to and from the pre-frontal cortex were cut from the brain. A lobotomy usually resulted in a serious loss of cognitive function.
Defeen tried to have Triclops lobotomized at the Imperial Reprogramming Institute.
While imprisoned on the first Death Star, Princess Leia Organa remembered being threatened with being "lobotomized and then taken to one of the barracks' pleasure houses".
An operation needed to lobotimize a Coruscani ogre and implant them with cybernetics was less expensive when compared to purchasing a new droid.
During the production of Star Wars: Episode V The Empire Strikes Back, it was decided that the talkative character of "Lando's aide" would be muted due to his cybernetic implants lobotomizing him. As a reference to this change, the character was named "Lobot," a corruption of the word "lobotomy."