Crack cocaine and Cocain

Crack cocaine noun - A purified and potent form of cocaine that is smoked rather than snorted; highly addictive.

Cocain and crack cocaine are semantically related. In some cases you can use "Cocain" instead a noun phrase "Crack cocaine".

Cocain noun - A narcotic (alkaloid) extracted from coca leaves; used as a surface anesthetic or taken for pleasure; can become powerfully addictive.

Crack cocaine and cocain are semantically related. Sometimes you can replace phrase "Crack cocaine" with "Cocain", this terms are similar.