Definition of "headcase" [headcase]

• A mentally unbalanced, unpredictable person, especially one who displays aggressive behavior. (noun)

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• "In the past he was known as a headcase, but it seems like he's learning to deal with the hard fouls and is keeping his once infamous temper in control. getting into an altercation as the crowd rushed the court in South Carolina after one of Kentucky's two loses on the season."
• "If he was on the sidelines crying about it, he would be called a headcase like Vince Young."
• "Each time we visited, she'd be drunk when we arrived, which would simply confirm my entrenched view of her as a hopeless headcase."