hunchbacked vs crookback

hunchbacked is not a noun while crookback is a noun.

Word	Noun	Adjective	Verb	Adverb
hunchbacked	No	Yes	No	No
crookback	Yes	Yes	No	No

As adjectives, hunchbacked and crookback are synonyms defined as:

hunchbacked and crookback: characteristic of or suffering from kyphosis, an abnormality of the vertebral column

Other synonyms of hunchbacked include crookbacked, gibbous, humpbacked, humped, kyphotic.

hunchbacked (noun)	crookback (noun)
	a person whose back is hunched because of abnormal curvature of the upper spine

hunchbacked (adjective)	crookback (adjective)
characteristic of or suffering from kyphosis, an abnormality of the vertebral column	characteristic of or suffering from kyphosis, an abnormality of the vertebral column