Mentally deranged, especially as manifested in a wild or aggressive way. adjective
He was acting crazy and shouting at everyone.
The movie portrayed a crazy scientist who wanted to take over the world.
Extremely enthusiastic or passionate about something. adjective
She's crazy about jazz music and attends every concert she can.
He's crazy for vintage cars and spends weekends restoring them.
Extremely foolish or impractical. adjective
It would be crazy to climb that mountain without proper gear.
Starting a business without a plan is a crazy idea.
Very intense or extreme. adjective
The party last night was crazy, with music blasting until dawn.
The traffic was crazy during the holiday weekend.
A person who is mentally deranged. noun
The town's crazy was known for wandering the streets and talking to himself.
In the story, the crazy was locked away in the attic.