The Collaborative International Dictionary of English v.0.48:

Nonone \Non"one\, n. [Nonane + -one, suffix denoting the third
   degree of unsaturation.] (Chem.)
   1. Any one of several metameric unsaturated hydrocarbons
      (C9H14) of the valylene series. [archaic?]
      [1913 Webster]

   2. Any of several isomeric ketones (C9H18O) conceptually
      derived from nonane by substituting an oxygen for two
      hydrogen atoms on one of the non-terminal carbon atoms.
      [PJC]