The word "idiot" is a popular word to use when describing a person as stupid or careless, or when expressing unhappiness with another person’s decision. (This word is a noun).
That idiot is driving the wrong way on a one-way street.
Rosa says her boss is an idiot.
He’s an idiot for leaving his kids in the car on a hot summer day.
What kind of an idiot would do that?
There’s an idiot down the street who cuts his grass at seven in the morning.
Everyone said that Ned was an idiot for what he did.
The word "idiocy" is also a noun. It describes a situation:
To continue doing the same thing over and over again, despite the negative consequences, is sheer idiocy.
Human beings can’t seem to shake the idiocy of war.
The word "idiotic" is an adjective.
That’s an idiotic idea.
Whose idiotic decision was this?
Some idiotic people are making noise down the street.
Sarah came up with an idiotic reason for leaving class early.
