Green’s Dictionary of Slang

ecstasy n.

also ecstacy
[ecstasy existed in the 1960s as one of many synthetic hallucinogens (although it is more amphetamine than a ‘real’ hallucinogen) from a group known as ‘Schulgin’s compounds’; it only reached its apotheosis in the late 1980s. Its nickname comes from the indiscriminate affection that its ingestion promotes, and the earlier popular name of ‘love-drug’; virtually SE by late 1990s]

[1980s+] a name for the drug known officially as methylenedioxymethamphetamine (MDMA).