The Collaborative International Dictionary of English v.0.48:
Carburetor \Car"bu*ret`or\, Carburettor \Car"bu*ret`tor\, n.
1. (Chem.) An apparatus in which coal gas, hydrogen, or air
is passed through or over a volatile hydrocarbon, in order
to confer or increase illuminating power. [Written also
carburettor.]
[1913 Webster]
2. One that carburets; specif., an apparatus in which air or
gas is carbureted, as by passing it through a light
petroleum oil. The carburetor for a gasoline engine is
usually either a surface carburetor, or alternatively a
float carburetor (called also float-feed carburetor,
or spray carburetor). In the former air is charged by
being passed over the surface of gasoline. In the latter a
fine spray of gasoline is drawn from an atomizing nozzle
by a current of air induced by the suction of the engine
piston, the supply of gasoline being regulated by a float
which actuates a needle valve controlling the outlet of
the feed pipe. Alcohol and other volatile inflammable
liquids may be used instead of gasoline.
[Webster 1913 Suppl.]