Source : Webster's Revised Unabridged Dictionary (1913)

Quinone \Qui"none\, n. [Quinine + ketone.] (Chem.)
   A crystalline substance, {C6H4O2} (called also
   {benzoketone}), first obtained by the oxidation of quinic
   acid and regarded as a double ketone; also, by extension, any
   one of the series of which quinone proper is the type.
   [Written also {chinone}, {kinone}.]

Source : WordNet®

quinone
     n : any of a class of aromatic yellow compounds including
         several that are biologically important as coenzymes or
         acceptors or vitamins; used in making dyes [syn: {benzoquinone}]