A tabu is something that is not allowed or is forbidden in a certain culture or society.
The word tabu can make people think of strong rules, traditions, or things that are not okay to do.
Examples:
In some places, it is tabu to eat certain animals.
It's tabu to talk about that here.
Wearing hats indoors is tabu in some places.
It's tabu to eat ice cream for breakfast!
In some cultures, it's tabu to whistle at night.
It's tabu to wear shoes in the house in some places.