Source : Webster's Revised Unabridged Dictionary (1913)

Octane \Oc"tane\, n. [See {Octa-}] . (Chem.)
   Any one of a group of metametric hydrocarcons ({C8H18}) of
   the methane series. The most important is a colorless,
   volatile, inflammable liquid, found in petroleum, and a
   constituent of benzene or ligroin.

Dibutyl \Di*bu"tyl\, n. [Pref. di- + butyl.] (Chem.)
   A liquid hydrocarbon, {C8H18}, of the marsh-gas series, being
   one of several octanes, and consisting of two butyl radicals.
   Cf. {Octane}.