\Ben"zene\, n. [From {Benzoin}.] (Chem.)
A volatile, very inflammable liquid, {C6H6}, contained in the
naphtha produced by the destructive distillation of coal,
from which it is separated by fractional distillation. The
name is sometimes applied also to the impure commercial
product or benzole, and also, but rarely, to a similar mixed
product of petroleum.
{Benzene nucleus}, {Benzene ring} (Chem.), a closed chain or
   ring, consisting of six carbon atoms, each with one
   hydrogen atom attached, regarded as the type from which
   the aromatic compounds are derived. This ring formula is
   provisionally accepted as representing the probable
   constitution of the benzene molecule, {C6H6}, and as the
   type on which its derivatives are formed.