Source : Webster's Revised Unabridged Dictionary (1913)

Crookback \Crook"back`\ (kr??k"b?k), n.
   A crooked back; one who has a crooked or deformed back; a
   hunchback.

Source : WordNet®

crookback
     n : a person whose back is hunched because of abnormal curvature
         of the upper spine [syn: {humpback}, {hunchback}]

crookback
     adj : characteristic of or suffering from kyphosis, an abnormality
           of the vertebral column [syn: {crookbacked}, {humped},
           {humpbacked}, {hunchback}, {hunchbacked}, {gibbous}, {kyphotic}]