People who take things secretly from one place to another, especially things that are not allowed to be taken.
Smugglers are usually seen as bad because they break the rules and the law.
Examples:
The smugglers hid the things in their bags.
The police caught the smugglers at the border.
The smugglers tried to bring in things that were not allowed.
The smugglers thought they were very clever, but they got caught.
The smugglers were like pirates, but on land.
The story of the smugglers was in the news.