Source : Webster's Revised Unabridged Dictionary (1913)

Hogback \Hog"back`\, n.
   1. (Arch.) An upward curve or very obtuse angle in the upper
      surface of any member, as of a timber laid horizontally;
      -- the opposite of camber.

   2. (Naut.) See {Hogframe}.

   3. (Geol.) A ridge formed by tilted strata; hence, any ridge
      with a sharp summit, and steeply sloping sides.

Source : WordNet®

hogback
     n : a narrow ridge of hills [syn: {horseback}]