hunchback vs kyphosis

hunchback and kyphosis both are nouns.

Word	Noun	Adjective	Verb	Adverb
hunchback	Yes	No	No	No
kyphosis	Yes	No	No	No

As nouns, hunchback and kyphosis are synonyms defined as:

hunchback and kyphosis: an abnormal backward curve to the vertebral column

Other synonyms of hunchback include humpback.

hunchback (noun)	kyphosis (noun)
a person whose back is hunched because of abnormal curvature of the upper spine	The property of having an abnormal convex curvature in the cervical or lumbar regions of the spine.
an abnormal backward curve to the vertebral column	an abnormal backward curve to the vertebral column