The Collaborative International Dictionary of English v.0.48:

jean \jean\ (j[=a]n), n. [Prob. named from Genoa. See Jane.]
   1. A twilled cotton cloth.
      [1913 Webster]

   2. (pl.) (j[=e]nz), Same as blue jeans.
      [PJC]

   3. (pl.) (j[=e]nz), Pants made of different fabrics,
      resembling blue jeans.
      [PJC]

   Satin jean, a kind of jean woven smooth and glossy, after
      the manner of satin.
      [1913 Webster]