mdma(n = noun.artifact) methylenedioxymethamphetamine - a stimulant drug that is chemically related to mescaline and amphetamine and is used illicitly for its euphoric and hallucinogenic effects; it was formerly used in psychotherapy but in 1985 it was declared illegal in the United States; "MDMA is often used at parties because it enables partygoers to remain active for long periods of time"
is a kind of club drug
has particulars: adam, cristal, disco biscuit, ecstasy, go, hug drug, x, xtc

   Methylenedioxymethamphetamine, a drug designed to have the effects of amphetamines but originally synthesized to avoid the drug laws; it is now a controlled substance. It is informally called ecstasy. It is used by some abusively and illegally without a prescription. [WordNet 1.5]

mdma, abbr. methylenedioxymethamphetamine, an amphetamine-based drug that causes euphoric and hallucinatory effects, originally produced as an appetite suppressant (see ECSTASY 3).