madmadmadsmaddedmaddingadjective (madder, maddest)1ill in your mindsame meaningcrazy2(British, informal) very stupidsame meaningcrazy: I think you're mad to go out in this snow!3(American, informal) very angry: He was mad at me for losing his watch.be mad about somebody or something (informal) to like somebody or something very much: Mina is mad about computer games. He's mad about her.drive somebody madto make somebody very angry: This noise is driving me mad!go mad (British, informal)1to become ill in your mind: He went mad and killed himself.2to become very angry: Mum will go mad when she finds out what you did at school.like mad (informal) very hard, fast, much, etc.: I had to run like mad to catch the bus.