Wiktionary
n. A drug commonly associated with dance clubs and raves.
WordNet
n. a controlled subtance that is usually taken by young people at dance clubs and raves
Wikipedia
Club drugs, also called rave drugs, are a loosely defined category of recreational drugs which are associated with discothèques in the 1970s and dance clubs, parties, and raves in the 1980s to the 2000s. Unlike many other categories, such as opiates, which are established according to pharmaceutical properties, club drugs are a "category of convenience" which includes drugs ranging from entactogens and inhalants to stimulants and psychedelics. Dancers at all-night parties have used these drugs for their stimulating or psychedelic properties. "Club drugs" vary by country and region; in some areas, even opiates such as heroin have been sold at clubs, though this practice is relatively uncommon.