Not according to, or authorized by, law; specif., contrary to, or in violation of, human law; unlawful; illicit; hence, immoral; as, an illegal act; illegal trade; illegal love.

Doing something against the rules that is cause for disqualification.

Something is illegal when it violates a statute, regulation or other law.

not in accordance with the laws.

an intelligence officer or a recruited agent who operates in a foreign country in the guise of a private person, and is often present under false identity

A KGB operative infiltrated into a target country and operating without the protection of diplomatic immunity.

Within the context of a computer program, this refers to any operation that attempts to access an area of memory or perform an instruction that is not...