The Collaborative International Dictionary of English v.0.48:

Hexane \Hex"ane\, n. [Gr. "e`x six.] (Chem.)
   Any one of five hydrocarbons, C6H14, of the paraffin
   series. They are colorless, volatile liquids, and are so
   called because the molecule has six carbon atoms.
   [1913 Webster]