Screwy means strange, mixed-up, or not working the way it should. When something goes screwy, it becomes confusing or unpredictable. If your computer starts acting screwy, programs might freeze, windows might open randomly, or files might disappear for no clear reason. When plans go screwy, what should have been simple becomes complicated and frustrating.

The word has an informal, slightly playful feeling to it. You might say the weather's been screwy lately if it snows one day and feels like spring the next. A teacher might notice a student's usually excellent work has gotten screwy, full of careless mistakes that don't make sense.

Screwy can also describe a person who seems eccentric or whose thinking doesn't quite add up. Someone with screwy ideas might believe wild conspiracy theories or make decisions that baffle everyone around them. The word suggests something's off, twisted, or not quite right, like a screw that's been put in crooked and now everything it holds together wobbles a bit.