double bubble
noun
1
an amount that is twice as much, especially money. A rhyming play on 'double' UK, 1999.
2
overtime at double rate UK, 2005.
3
a water pipe with two channels, used for smoking marijuana US, 1998.
4
cocaine in a smokable form. Marketed as being twice as potent when inhaled US, 1993.
5
in prison, interest demanded on an advance of drugs, tobacco or any other form of prison currency. With variant 'double back' UK, 1996.
6
a very attractive girl. Teen slang US, 1951