The Collaborative International Dictionary of English v.0.48:

Hunchback \Hunch"back`\, n. [Cf. Humpback.]
   A back with a hunch or hump; also, a hunchbacked person.
   [1913 Webster]

WordNet (r) 3.0 (2006):

hunchback
    n 1: an abnormal backward curve to the vertebral column [syn:
         kyphosis, humpback, hunchback]
    2: a person whose back is hunched because of abnormal curvature
       of the upper spine [syn: humpback, hunchback,
       crookback]