mistake

noun
UK /mɪˈsteɪk/
US /mɪˈsteɪk/

A mistake is something you do that is not right.

I made a mistake on my math test.


OTHER MEANINGS

2. To not understand something correctly.

She mistook the salt for sugar.

3. To wrongly think someone or something is another person or thing.

People often mistake him for his twin brother.

4. A wrong action or decision that causes a problem.

It was a mistake to leave the door open.