Drug
Drug has a hard definition. It also called as medicine which are commonly considered to be drugs but which are not commonly used as medicine. According to Agensi Dadah Kebangsaan, drug is any chemical substance which affects the human physiology or psychology. The substance may be habit-forming and perhaps addictive.
According to mass communication and vernacular usage, the term "drug abuse" may be used in newspapers, television, etc. in an ambiguous, catch-all sense rather than as a medical or legal term, sometimes disapprovingly to refer to any drug use at all, particularly of illicit drugs .A common misconception perpetuated by mainstream media and anti-drug campaigns is that "if you do drugs once, you're automatically an addict".