crack: a purified and potent form of cocaine that is smoked rather than snorted; highly addictive
cocaine: a narcotic (alkaloid) extracted from coca leaves; used as a surface anesthetic or taken for pleasure; can become powerfully addictive
islamic calendar: the lunar calendar used by Muslims; dates from 622 AD (the year of the Hegira); the beginning of the Muslim year retrogresses through the solar year completing the cycle every 32 years