0 brainless brainless [adjective]Stupid US /ˈbreɪn.ləs/ UK /ˈbreɪn.ləs/ Example: What sort of brainless idiot would do that? Longman Dictionary of Contemporary English brainless brain‧less /ˈbreɪnləs/ BrE AmE adjective completely stupid: What a brainless thing to do! Oxford Advanced Learner's Dictionary brainless brain·less [brainless] [ˈbreɪnləs] [ˈbreɪnləs] adjective stupid; not able to think or talk in an intelligent way • Her husband's colleagues were brainless bores. Cambridge Advanced Learner's Dictionary Cambridge Advanced Learner's Dictionary - 4th Edition brainless / ˈbreɪn.ləs / adjective informal stupid: What sort of brainless idiot would do that? © Cambridge University Press 2013 Collins COBUILD Advanced Learner’s English Dictionary brainless /breɪnləs/ If you describe someone or something as brainless, you mean that you think they are stupid. I got treated as if I was a bit brainless. = stupid ADJ [disapproval] Merriam-Webster's Advanced Learner's Dictionary Merriam-Webster's Advanced Learner's Dictionary: brainless brain·less /ˈbreɪnləs/ adj [more ~; most ~] informal : very stupid or silly • He thought most of his coworkers were brainless. • The plot of the new movie is brainless and the acting is terrible. - brain·less·ly adv - brain·less·ness noun [noncount] American EnglishBritish Englishstupid and sillyadjective