be brain dead

be brain dead

1. Literally, to lack brain activity, as after a brain injury. After the car accident, Kendra was brain dead. Despite the surgeon's best efforts, the patient was brain dead.
2. slang To be so mentally exhausted or lacking focus that one does something poorly and/or makes easily avoidable mistakes. Did I just say that two plus two equals five? Wow, I'm really brain dead today.
See also: brain, dead
References in periodicals archive ?
The pertinent remark that Levin and Whyte made 30 years ago, namely that "Clinical criteria make it possible to be brain dead in one country and not in another" (4:852) proved to be perpetually valid (5-7).
The new laws also allow a person to be an organ or tissue donor if they die in an automobile accident or are certified to be brain dead.
You can either be mindful of what you put into your mouth or be brain dead and let the drug companies decide for you.
Officials at the Furukawa hospital explained to reporters the procedures taken to save the life of the donor and, after he died, how he was confirmed to be brain dead.
You have to be brain dead to sit in an Imax theatre and not say, "Holy cow, this is a hell-of-a-lot better." 35mm was invented in the 19th century.