A spy working abroad illegally and undercover, without visible ties to his or her country’s authorities.
An illegal immigrant.
Contraband, esp. illegal substances such as drugs.
Contrary to or forbidden by law, especially criminal law.
Breaching certain enacted statutes of positive law; not lawful, not legal (cf. immoral, unethical)
Forbidden by established rules.
Being or doing something illegally.
Being an illegal immigrant; residing in a country illegally.
Totally fictitious, and often issued on behalf of a non-existent territory or country.
A person who is within the boundaries of a political state without the authorization of the government of that state; a national of another country who has entered or stayed without permission.