非法 (fēi fǎ): illegal

During an inspection, police discovered that this factory was secretly discharging wastewater, which is illegal pollution, and immediately ordered it to stop production.

In order to make quick money, he got involved in illegal gambling, ended up losing all his savings, and was detained by the police.

This company was fined five million yuan by the regulatory authorities for illegally obtaining users' personal information.

In some countries, performing on the street without a permit is illegal and may result in a fine or deportation.

Doctors warn that weight-loss pills bought through illegal channels often contain dangerous ingredients and may harm your health after taking them.