carburetor

Etymology

From the verb carburate, carburet (“to mix (air) with hydrocarbons”).

noun

1. (US, Canada) A device in an internal combustion engine where fuel is vaporized and mixed with air prior to ignition.
2. (slang, drugs) A water pipe or bong; a device or contrivance for mixing air with burning cannabis or cocaine.
   Variations on the bong included air-driven pipes, electric pipes, ice pipes (chillers), mask pipes, chamber pipes, and carburetor pipes. 1989, United States International Trade Commission, Importation of certain drug paraphernalia into the United States, page 8
   Some pipes feature a “carburetor,” which is a small hole in the air chamber located past the bowl. The carburetor is held shut while the bowl is being lit and the smoke drawn. 2008, Dale Gieringer, Ed Rosenthal, Gregory Carter, Marijuana Medical Handbook, page 172