The Collaborative International Dictionary of English v.0.48:

Hendecane \Hen"de*cane\, n. [Gr. "e`ndeka eleven.] (Chem.)
   A hydrocarbon, C11H24, of the paraffin series; -- so called
   because it has eleven atoms of carbon in each molecule.
   Called also endecane, undecane.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Endecane \En"de*cane\, n. [Gr. ? eleven.] (Chem.)
   One of the higher hydrocarbons of the paraffin series,
   C11H24, found as a constituent of petroleum. [Written also
   hendecane.]
   [1913 Webster]