IPA: //ˈkɒntrəˌbænd//
KK: /ˈkɒntrəˌbænd/
Not allowed to be imported or exported, often because it is illegal or restricted.
The police seized a large amount of contraband goods at the border.
Items that are illegal to import or export, often because they are prohibited by law or treaty.
The police found a large amount of contraband hidden in the truck.
Contraband is formed from "contra-" (meaning against) and "band" (from the Old French "ban", meaning a proclamation or a ban). The word refers to goods that are prohibited or banned, hence, against the law.
Think of 'against' ('contra-') the law or a 'ban' on certain goods — that's why contraband refers to illegal items.