carburettor in British English
or carburetter (ˌkɑːbjʊˈrɛtə, ˈkɑːbjʊˌrɛtə, -bə-) or US carburetor (ˈkɑːbjʊˌreɪtə, -bə-)
nouna device used in petrol engines for atomizing the petrol, controlling its mixture with air, and regulating the intake of the air-petrol mixture into the engine
Informal term: carb. Compare fuel injection