savant syndrome vs backwardness

savant syndrome and backwardness both are nouns.

Word	Noun	Adjective	Verb	Adverb
savant syndrome	Yes	No	No	No
backwardness	Yes	No	No	No

As nouns, backwardness is a hypernym of savant syndrome; that is, backwardness is a word with a broader meaning than savant syndrome:

savant syndrome: A condition in which a person with a mental disability, such as an autism spectrum disorder, demonstrates profound and prodigious capacities or abilities far in excess of what would be considered normal.
backwardness: lack of normal development of intellectual capacities

Other hypernyms of savant syndrome include brilliance, genius, mental retardation, retardation, slowness, subnormality.

savant syndrome (noun)	backwardness (noun)
A condition in which a person with a mental disability, such as an autism spectrum disorder, demonstrates profound and prodigious capacities or abilities far in excess of what would be considered normal.	lack of normal development of intellectual capacities