The Collaborative International Dictionary of English v.0.48:

Nonane \Non"ane\, n. [L. nonus ninth.] (Chem.)
   One of a group of metameric hydrocarbons C9H20 of the
   paraffin series; -- so called because of the nine carbon
   atoms in the molecule. Normal nonane is a colorless
   volatile liquid, an ingredient of ordinary kerosene.
   [1913 Webster]