ma·ni·a·cal 
(mə-nīə-kəl) also ma·ni·ac (mānē-ăk′)
(mə-nīə-kəl) also ma·ni·ac (mānē-ăk′)adj.
1. Suggestive of or afflicted with extreme mental derangement: a maniacal frenzy.
2. Characterized by excessive enthusiasm or excitement: a maniacal interest in gambling.
3. Wildly irresponsible: maniacal drivers.
ma·nia·cal·ly adv.