brain-dead /ˈbɹeɪnˌdɛd/adjective 2noun 1forms 3 adjective2 •Having an irreversible loss of brain function and cessation of brain activity. •(informal) Having no useful thoughts; stupid; ditzy."AI has been brain-dead since the 1970s," said AI guru Marvin Minsky in a recent speech at Boston University. Minsky co-founded the MIT Artificial Intelligence Laboratory in 1959 with John McCarthy. — 2003 noun1 •(informal, offensive) An unintelligent person."What makes you different from all the other brain-deads that come through here?" — 2015 formsbrain-deads · more brain-dead · most brain-dead