Green’s Dictionary of Slang

a form of methamphetamine, orig. created by Nazi chemists during WWII, but particularly popular in Thailand.

1999		Observer 17 Oct. 5: The so-called Nazi method of making yaba was first noticed in Thailand more than 30 years ago.
2000		Guardian Travel 15 Jan. 3: Yabba, a kind of nuclear amphetamine which, if smoked in silver foil, will keep you going forever.
2002		Associated Press 22 Sept. 🌐 But what may seem as harmless as candy is a new form of methamphetamine called ya ba, a Thai name meaning ‘crazy drug.’ It is said to be significantly more powerful – and dangerous – than the current club drug of choice, Ecstasy.