illicit

Refers to illegal narcotic substances.

A secret sexual relationship between two people when one or both are married to someone else.

非法物质

A general term for any illegal controlled material.

被法律、规则或习俗禁止的物质

非法贸易

Illegal commerce, such as smuggling.

被法律、规则或习俗禁止的贸易；通常带有道德层面。

违禁麻醉品

A more formal or legal term for an illegal drug.

未经法律许可或授权的麻醉品

不正当性行为

Sexual activity that is considered morally or legally wrong.

被认为在道德上或法律上是错误的的性活动。

非法使用

The illegal or unauthorized use of something, often followed by 'of' (e.g., illicit use of funds).

对某物的非法或未经授权的使用，常后接 'of' (例如，非法使用资金)。

非法经济

The part of an economy based on illegal activities (also shadow economy).

经济中基于非法活动的部分（也称影子经济）。

Refers to smuggled or untaxed cigarettes.