Akademik

a narcotic that is considered relatively strong and likely to cause addiction

an addicting drug capable of producing severe physical or psychological dependence, as heroin.

[1965-70, Amer.]

hard drug UK US noun [countable] [singular hard drug plural hard drugs]

an illegal drug such as heroin that is addictive

Thesaurus: illegal drugs and drugs sometimes taken illegally_hyponym

hard drug,

any drug that is physically and psychologically addictive, such as heroin.

ˌhard ˈdrug [hard drug] noun usually plural

a powerful illegal drug, such as ↑heroin, that some people take for pleasure and can become ↑addicted to

compare ↑soft drug