The Collaborative International Dictionary of English v.0.48:

Hexdecyl \Hex"de*cyl\, n. [Hex- + decyl.] (Chem.)
   The essential radical, C16H33, of hecdecane.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Cetyl \Ce"tyl\, n. [Gr. ? whale + -yl.] (Chem.)
   A radical, C16H33, not yet isolated, but supposed to exist
   in a series of compounds homologous with the ethyl compounds,
   and derived from spermaceti.
   [1913 Webster]