A more thorough explanation:

Definition: Delirium is a mental state that can happen when someone is sick. It can cause confusion, disorientation, and hallucinations. It can also be a state of exaggerated excitement or a delusion.

• When my grandfather had a high fever, he experienced delirium and thought he was back in his childhood home.
• The concert-goers were in a state of delirium as their favorite band took the stage.
• She was convinced that the government was spying on her, but it was just a delirium caused by her fever.

The first example shows how delirium can cause hallucinations and confusion. The second example illustrates how delirium can be a state of exaggerated excitement. The third example demonstrates how delirium can cause delusions, which are false beliefs that someone holds even when presented with evidence to the contrary.