illicit

Refers to illegal narcotic substances.

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

A general term for any illegal controlled material.

Illegal commerce, such as smuggling.

A more formal or legal term for an illegal drug.

Sexual activity that is considered morally or legally wrong.

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

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

Refers to smuggled or untaxed cigarettes.