madness

noun

the state of having a serious mental illness

Usage: formal

extremely foolish or unreasonable behavior
a state of wild excitement or enthusiasm

Examples

The king’s madness led to his removal from the throne.
It would be madness to drive in this storm.
The crowd was caught up in the madness of the celebration.
She questioned the madness of spending so much money on a car.
March Madness brings excitement to college basketball fans.
The madness in his eyes frightened everyone around him.
There’s a method to his madness, even if it’s not obvious.