The Collaborative International Dictionary of English v.0.48:

Cetylic \Ce*tyl"ic\, a. (Chem.)
   Of, pertaining to, or derived from, spermaceti.
   [1913 Webster]

   Cetylic alcohol (Chem.), a white, waxy, crystalline solid,
      obtained from spermaceti, and regarded as homologous with
      ordinary, or ethyl, alcohol; ethal; -- called also cetyl
      alcohol.
      [1913 Webster]