Academic English #66. big no-no: Something Absolutely Forbidden (a Taboo)

In English, "big no-no" is a very common expression in everyday conversation,

and it means “something absolutely forbidden” or “a taboo.”

It can be used lightly, almost like a joke, or more seriously to emphasize a rule or taboo. In other words, you can understand “That’s a big no-no” to mean “That’s not allowed.”

3 Everyday English Examples

• Saying that on a first date is a big no-no.
• Wearing shoes in the kitchen is a big no-no.
• Checking your phone during the exam is a big no-no.

3 Academic/Professional English Examples

• Data manipulation in academic presentations is a big no-no.
• Sharing patient records without consent is a big no-no in medical ethics.
• Ignoring the time limit at an international conference is a big no-no.