The Collaborative International Dictionary of English v.0.48:

Aromatic \Ar`o*mat"ic\, Aromatical \Ar`o*mat"ic*al\, a. [L.
   aromaticus, Gr. ?: cf. F. aromatique. See Aroma.]
   Pertaining to, or containing, aroma; fragrant; spicy;
   strong-scented; odoriferous; as, aromatic balsam.
   [1913 Webster]

   Aromatic compound (Chem.), one of a large class of organic
      substances, as the oils of bitter almonds, wintergreen,
      and turpentine, the balsams, camphors, etc., many of which
      have an aromatic odor. They include many of the most
      important of the carbon compounds and may all be derived
      from the benzene group, C6H6. The term is extended also
      to many of their derivatives.

   Aromatic vinegar. See under Vinegar.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Dipropargyl \Di`pro*par"gyl\, n. [Prefix di- + propargyl.]
   (Chem.)
   A pungent, mobile, volatile liquid, C6H6, produced
   artificially from certain allyl derivatives. Though isomeric
   with benzine, it is very different in its chemical relations.
   Called also dipropinyl.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Benzene \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.
   [1913 Webster]

   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.
      [1913 Webster]