Home › Words › M › madbrainmadbrainmadbrain means A rash, hotheaded or crazy person.EtymologyFrom mad + brain.nounA rash, hotheaded or crazy person.Definitions & examples from Wiktionary (CC BY-SA 3.0).Words closest in meaningBy meaning, not spelling — each word's AI semantic fingerprint, nearest first.madbrained 68% match — madcap; crazy vs madbrain →crackbrain 66% match — An eccentric or crazy person. vs madbrain →crazyhead 65% match — A crazy person; an eccentric. vs madbrain →madperson 65% match — A madman or madwoman. vs madbrain →brainish 64% match — hot-headed; furious vs madbrain →rattlebrain 63% match — A rattlebrained person. vs madbrain →madman 63% match — A man who is insane or mentally disturbed. vs madbrain →maddie 61% match — A mad person. vs madbrain →