{s} insane, affected by mania; acting in an abnormally enthusiastic or excited manner
disapproval If you describe someone's behaviour as maniacal, you mean that it is extreme, violent, or very determined, as if the person were insane. He was almost maniacal in his pursuit of sporting records She is hunched forward over the wheel with a maniacal expression. + maniacally ma·nia·cal·ly He was last seen striding maniacally to the hotel reception. behaving as if you are crazy